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and teach ANALYZE to compute such stats for tables that have subclasses. Per my proposal of yesterday. autovacuum still needs to be taught about running ANALYZE on parent tables when their subclasses change, but the feature is useful even without that.
7645 lines
248 KiB
Plaintext
7645 lines
248 KiB
Plaintext
<!-- $PostgreSQL: pgsql/doc/src/sgml/catalogs.sgml,v 2.215 2009/12/29 20:11:42 tgl Exp $ -->
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<!--
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Documentation of the system catalogs, directed toward PostgreSQL developers
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-->
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<chapter id="catalogs">
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<title>System Catalogs</title>
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<para>
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The system catalogs are the place where a relational database
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management system stores schema metadata, such as information about
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tables and columns, and internal bookkeeping information.
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<productname>PostgreSQL</productname>'s system catalogs are regular
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tables. You can drop and recreate the tables, add columns, insert
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and update values, and severely mess up your system that way.
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Normally, one should not change the system catalogs by hand, there
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are always SQL commands to do that. (For example, <command>CREATE
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DATABASE</command> inserts a row into the
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<structname>pg_database</structname> catalog — and actually
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creates the database on disk.) There are some exceptions for
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particularly esoteric operations, such as adding index access methods.
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</para>
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<sect1 id="catalogs-overview">
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<title>Overview</title>
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<para>
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<xref linkend="catalog-table"> lists the system catalogs.
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More detailed documentation of each catalog follows below.
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</para>
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<para>
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Most system catalogs are copied from the template database during
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database creation and are thereafter database-specific. A few
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catalogs are physically shared across all databases in a cluster;
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these are noted in the descriptions of the individual catalogs.
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</para>
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<table id="catalog-table">
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<title>System Catalogs</title>
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<tgroup cols="2">
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<thead>
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<row>
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<entry>Catalog Name</entry>
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<entry>Purpose</entry>
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</row>
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</thead>
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<tbody>
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<row>
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<entry><link linkend="catalog-pg-aggregate"><structname>pg_aggregate</structname></link></entry>
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<entry>aggregate functions</entry>
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</row>
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<row>
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<entry><link linkend="catalog-pg-am"><structname>pg_am</structname></link></entry>
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<entry>index access methods</entry>
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</row>
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<row>
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<entry><link linkend="catalog-pg-amop"><structname>pg_amop</structname></link></entry>
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<entry>access method operators</entry>
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</row>
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<row>
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<entry><link linkend="catalog-pg-amproc"><structname>pg_amproc</structname></link></entry>
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<entry>access method support procedures</entry>
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</row>
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<row>
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<entry><link linkend="catalog-pg-attrdef"><structname>pg_attrdef</structname></link></entry>
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<entry>column default values</entry>
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</row>
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<row>
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<entry><link linkend="catalog-pg-attribute"><structname>pg_attribute</structname></link></entry>
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<entry>table columns (<quote>attributes</quote>)</entry>
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</row>
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<row>
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<entry><link linkend="catalog-pg-authid"><structname>pg_authid</structname></link></entry>
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<entry>authorization identifiers (roles)</entry>
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</row>
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<row>
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<entry><link linkend="catalog-pg-auth-members"><structname>pg_auth_members</structname></link></entry>
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<entry>authorization identifier membership relationships</entry>
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</row>
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<row>
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<entry><link linkend="catalog-pg-cast"><structname>pg_cast</structname></link></entry>
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<entry>casts (data type conversions)</entry>
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</row>
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<row>
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<entry><link linkend="catalog-pg-class"><structname>pg_class</structname></link></entry>
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<entry>tables, indexes, sequences, views (<quote>relations</quote>)</entry>
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</row>
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<row>
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<entry><link linkend="catalog-pg-constraint"><structname>pg_constraint</structname></link></entry>
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<entry>check constraints, unique constraints, primary key constraints, foreign key constraints</entry>
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</row>
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<row>
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<entry><link linkend="catalog-pg-conversion"><structname>pg_conversion</structname></link></entry>
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<entry>encoding conversion information</entry>
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</row>
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<row>
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<entry><link linkend="catalog-pg-database"><structname>pg_database</structname></link></entry>
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<entry>databases within this database cluster</entry>
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</row>
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<row>
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<entry><link linkend="catalog-pg-default-acl"><structname>pg_default_acl</structname></link></entry>
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<entry>default privileges for object types</entry>
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</row>
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<row>
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<entry><link linkend="catalog-pg-depend"><structname>pg_depend</structname></link></entry>
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<entry>dependencies between database objects</entry>
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</row>
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<row>
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<entry><link linkend="catalog-pg-description"><structname>pg_description</structname></link></entry>
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<entry>descriptions or comments on database objects</entry>
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</row>
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<row>
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<entry><link linkend="catalog-pg-enum"><structname>pg_enum</structname></link></entry>
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<entry>enum label and value definitions</entry>
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</row>
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<row>
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<entry><link linkend="catalog-pg-foreign-data-wrapper"><structname>pg_foreign_data_wrapper</structname></link></entry>
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<entry>foreign-data wrapper definitions</entry>
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</row>
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<row>
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<entry><link linkend="catalog-pg-foreign-server"><structname>pg_foreign_server</structname></link></entry>
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<entry>foreign server definitions</entry>
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</row>
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<row>
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<entry><link linkend="catalog-pg-index"><structname>pg_index</structname></link></entry>
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<entry>additional index information</entry>
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</row>
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<row>
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<entry><link linkend="catalog-pg-inherits"><structname>pg_inherits</structname></link></entry>
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<entry>table inheritance hierarchy</entry>
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</row>
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<row>
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<entry><link linkend="catalog-pg-language"><structname>pg_language</structname></link></entry>
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<entry>languages for writing functions</entry>
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</row>
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<row>
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<entry><link linkend="catalog-pg-largeobject"><structname>pg_largeobject</structname></link></entry>
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<entry>data pages for large objects</entry>
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</row>
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<row>
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<entry><link linkend="catalog-pg-largeobject-metadata"><structname>pg_largeobject_metadata</structname></link></entry>
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<entry>metadata for large objects</entry>
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</row>
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<row>
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<entry><link linkend="catalog-pg-listener"><structname>pg_listener</structname></link></entry>
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<entry>asynchronous notification support</entry>
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</row>
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<row>
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<entry><link linkend="catalog-pg-namespace"><structname>pg_namespace</structname></link></entry>
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<entry>schemas</entry>
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</row>
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<row>
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<entry><link linkend="catalog-pg-opclass"><structname>pg_opclass</structname></link></entry>
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<entry>access method operator classes</entry>
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</row>
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<row>
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<entry><link linkend="catalog-pg-operator"><structname>pg_operator</structname></link></entry>
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<entry>operators</entry>
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</row>
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<row>
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<entry><link linkend="catalog-pg-opfamily"><structname>pg_opfamily</structname></link></entry>
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<entry>access method operator families</entry>
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</row>
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<row>
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<entry><link linkend="catalog-pg-pltemplate"><structname>pg_pltemplate</structname></link></entry>
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<entry>template data for procedural languages</entry>
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</row>
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<row>
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<entry><link linkend="catalog-pg-proc"><structname>pg_proc</structname></link></entry>
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<entry>functions and procedures</entry>
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</row>
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<row>
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<entry><link linkend="catalog-pg-rewrite"><structname>pg_rewrite</structname></link></entry>
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<entry>query rewrite rules</entry>
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</row>
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<row>
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<entry><link linkend="catalog-pg-db-role-setting"><structname>pg_db_role_setting</structname></link></entry>
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<entry>per-role and per-database settings</entry>
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</row>
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<row>
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<entry><link linkend="catalog-pg-shdepend"><structname>pg_shdepend</structname></link></entry>
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<entry>dependencies on shared objects</entry>
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</row>
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<row>
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<entry><link linkend="catalog-pg-shdescription"><structname>pg_shdescription</structname></link></entry>
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<entry>comments on shared objects</entry>
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</row>
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<row>
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<entry><link linkend="catalog-pg-statistic"><structname>pg_statistic</structname></link></entry>
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<entry>planner statistics</entry>
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</row>
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<row>
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<entry><link linkend="catalog-pg-tablespace"><structname>pg_tablespace</structname></link></entry>
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<entry>tablespaces within this database cluster</entry>
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</row>
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<row>
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<entry><link linkend="catalog-pg-trigger"><structname>pg_trigger</structname></link></entry>
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<entry>triggers</entry>
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</row>
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<row>
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<entry><link linkend="catalog-pg-ts-config"><structname>pg_ts_config</structname></link></entry>
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<entry>text search configurations</entry>
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</row>
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<row>
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<entry><link linkend="catalog-pg-ts-config-map"><structname>pg_ts_config_map</structname></link></entry>
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<entry>text search configurations' token mappings</entry>
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</row>
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<row>
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<entry><link linkend="catalog-pg-ts-dict"><structname>pg_ts_dict</structname></link></entry>
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<entry>text search dictionaries</entry>
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</row>
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<row>
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<entry><link linkend="catalog-pg-ts-parser"><structname>pg_ts_parser</structname></link></entry>
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<entry>text search parsers</entry>
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</row>
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<row>
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<entry><link linkend="catalog-pg-ts-template"><structname>pg_ts_template</structname></link></entry>
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<entry>text search templates</entry>
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</row>
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<row>
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<entry><link linkend="catalog-pg-type"><structname>pg_type</structname></link></entry>
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<entry>data types</entry>
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</row>
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<row>
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<entry><link linkend="catalog-pg-user-mapping"><structname>pg_user_mapping</structname></link></entry>
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<entry>mappings of users to foreign servers</entry>
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</row>
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</tbody>
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</tgroup>
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</table>
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</sect1>
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<sect1 id="catalog-pg-aggregate">
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<title><structname>pg_aggregate</structname></title>
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<indexterm zone="catalog-pg-aggregate">
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<primary>pg_aggregate</primary>
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</indexterm>
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<para>
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The catalog <structname>pg_aggregate</structname> stores information about
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aggregate functions. An aggregate function is a function that
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operates on a set of values (typically one column from each row
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that matches a query condition) and returns a single value computed
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from all these values. Typical aggregate functions are
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<function>sum</function>, <function>count</function>, and
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<function>max</function>. Each entry in
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<structname>pg_aggregate</structname> is an extension of an entry
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in <structname>pg_proc</structname>. The <structname>pg_proc</structname>
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entry carries the aggregate's name, input and output data types, and
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other information that is similar to ordinary functions.
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</para>
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<table>
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<title><structname>pg_aggregate</> Columns</title>
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<tgroup cols="4">
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<thead>
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<row>
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<entry>Name</entry>
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<entry>Type</entry>
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<entry>References</entry>
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<entry>Description</entry>
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</row>
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</thead>
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<tbody>
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<row>
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<entry><structfield>aggfnoid</structfield></entry>
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<entry><type>regproc</type></entry>
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<entry><literal><link linkend="catalog-pg-proc"><structname>pg_proc</structname></link>.oid</literal></entry>
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<entry><structname>pg_proc</structname> OID of the aggregate function</entry>
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</row>
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<row>
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<entry><structfield>aggtransfn</structfield></entry>
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<entry><type>regproc</type></entry>
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<entry><literal><link linkend="catalog-pg-proc"><structname>pg_proc</structname></link>.oid</literal></entry>
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<entry>Transition function</entry>
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</row>
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<row>
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<entry><structfield>aggfinalfn</structfield></entry>
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<entry><type>regproc</type></entry>
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<entry><literal><link linkend="catalog-pg-proc"><structname>pg_proc</structname></link>.oid</literal></entry>
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<entry>Final function (zero if none)</entry>
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</row>
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<row>
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<entry><structfield>aggsortop</structfield></entry>
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<entry><type>oid</type></entry>
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<entry><literal><link linkend="catalog-pg-operator"><structname>pg_operator</structname></link>.oid</literal></entry>
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<entry>Associated sort operator (zero if none)</entry>
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</row>
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<row>
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<entry><structfield>aggtranstype</structfield></entry>
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<entry><type>oid</type></entry>
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<entry><literal><link linkend="catalog-pg-type"><structname>pg_type</structname></link>.oid</literal></entry>
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<entry>Data type of the aggregate function's internal transition (state) data</entry>
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</row>
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<row>
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<entry><structfield>agginitval</structfield></entry>
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<entry><type>text</type></entry>
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<entry></entry>
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<entry>
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The initial value of the transition state. This is a text
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field containing the initial value in its external string
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representation. If this field is NULL, the transition state
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value starts out NULL
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</entry>
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</row>
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</tbody>
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</tgroup>
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</table>
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<para>
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New aggregate functions are registered with the <xref
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linkend="sql-createaggregate" endterm="sql-createaggregate-title">
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command. See <xref linkend="xaggr"> for more information about
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writing aggregate functions and the meaning of the transition
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functions, etc.
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</para>
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</sect1>
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<sect1 id="catalog-pg-am">
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<title><structname>pg_am</structname></title>
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<indexterm zone="catalog-pg-am">
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<primary>pg_am</primary>
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</indexterm>
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<para>
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The catalog <structname>pg_am</structname> stores information about index
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access methods. There is one row for each index access method supported by
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the system. The contents of this catalog are discussed in detail in
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<xref linkend="indexam">.
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</para>
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<table>
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<title><structname>pg_am</> Columns</title>
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<tgroup cols="4">
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<thead>
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<row>
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<entry>Name</entry>
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<entry>Type</entry>
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<entry>References</entry>
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<entry>Description</entry>
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</row>
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</thead>
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<tbody>
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<row>
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<entry><structfield>amname</structfield></entry>
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<entry><type>name</type></entry>
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<entry></entry>
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<entry>Name of the access method</entry>
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</row>
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<row>
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<entry><structfield>amstrategies</structfield></entry>
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<entry><type>int2</type></entry>
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<entry></entry>
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<entry>Number of operator strategies for this access method,
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or zero if access method does not have a fixed set of operator
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strategies</entry>
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</row>
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<row>
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<entry><structfield>amsupport</structfield></entry>
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<entry><type>int2</type></entry>
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<entry></entry>
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<entry>Number of support routines for this access method</entry>
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</row>
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<row>
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<entry><structfield>amcanorder</structfield></entry>
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<entry><type>bool</type></entry>
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<entry></entry>
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<entry>Does the access method support ordered scans?</entry>
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</row>
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<row>
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<entry><structfield>amcanbackward</structfield></entry>
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<entry><type>bool</type></entry>
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<entry></entry>
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<entry>Does the access method support backward scanning?</entry>
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</row>
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<row>
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<entry><structfield>amcanunique</structfield></entry>
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<entry><type>bool</type></entry>
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<entry></entry>
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<entry>Does the access method support unique indexes?</entry>
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</row>
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<row>
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<entry><structfield>amcanmulticol</structfield></entry>
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<entry><type>bool</type></entry>
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<entry></entry>
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<entry>Does the access method support multicolumn indexes?</entry>
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</row>
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<row>
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<entry><structfield>amoptionalkey</structfield></entry>
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<entry><type>bool</type></entry>
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<entry></entry>
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<entry>Does the access method support a scan without any constraint
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for the first index column?</entry>
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</row>
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|
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<row>
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|
<entry><structfield>amindexnulls</structfield></entry>
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<entry><type>bool</type></entry>
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<entry></entry>
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<entry>Does the access method support null index entries?</entry>
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|
</row>
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|
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<row>
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|
<entry><structfield>amsearchnulls</structfield></entry>
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<entry><type>bool</type></entry>
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<entry></entry>
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<entry>Does the access method support IS NULL searches?</entry>
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|
</row>
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|
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<row>
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|
<entry><structfield>amstorage</structfield></entry>
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<entry><type>bool</type></entry>
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<entry></entry>
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<entry>Can index storage data type differ from column data type?</entry>
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</row>
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<row>
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|
<entry><structfield>amclusterable</structfield></entry>
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<entry><type>bool</type></entry>
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<entry></entry>
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<entry>Can an index of this type be clustered on?</entry>
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</row>
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|
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<row>
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|
<entry><structfield>amkeytype</structfield></entry>
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<entry><type>oid</type></entry>
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<entry><literal><link linkend="catalog-pg-type"><structname>pg_type</structname></link>.oid</literal></entry>
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<entry>Type of data stored in index, or zero if not a fixed type</entry>
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</row>
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|
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<row>
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|
<entry><structfield>aminsert</structfield></entry>
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|
<entry><type>regproc</type></entry>
|
|
<entry><literal><link linkend="catalog-pg-proc"><structname>pg_proc</structname></link>.oid</literal></entry>
|
|
<entry><quote>Insert this tuple</quote> function</entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry><structfield>ambeginscan</structfield></entry>
|
|
<entry><type>regproc</type></entry>
|
|
<entry><literal><link linkend="catalog-pg-proc"><structname>pg_proc</structname></link>.oid</literal></entry>
|
|
<entry><quote>Start new scan</quote> function</entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry><structfield>amgettuple</structfield></entry>
|
|
<entry><type>regproc</type></entry>
|
|
<entry><literal><link linkend="catalog-pg-proc"><structname>pg_proc</structname></link>.oid</literal></entry>
|
|
<entry><quote>Next valid tuple</quote> function, or zero if none</entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry><structfield>amgetbitmap</structfield></entry>
|
|
<entry><type>regproc</type></entry>
|
|
<entry><literal><link linkend="catalog-pg-proc"><structname>pg_proc</structname></link>.oid</literal></entry>
|
|
<entry><quote>Fetch all valid tuples</quote> function, or zero if none</entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry><structfield>amrescan</structfield></entry>
|
|
<entry><type>regproc</type></entry>
|
|
<entry><literal><link linkend="catalog-pg-proc"><structname>pg_proc</structname></link>.oid</literal></entry>
|
|
<entry><quote>Restart this scan</quote> function</entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry><structfield>amendscan</structfield></entry>
|
|
<entry><type>regproc</type></entry>
|
|
<entry><literal><link linkend="catalog-pg-proc"><structname>pg_proc</structname></link>.oid</literal></entry>
|
|
<entry><quote>End this scan</quote> function</entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry><structfield>ammarkpos</structfield></entry>
|
|
<entry><type>regproc</type></entry>
|
|
<entry><literal><link linkend="catalog-pg-proc"><structname>pg_proc</structname></link>.oid</literal></entry>
|
|
<entry><quote>Mark current scan position</quote> function</entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry><structfield>amrestrpos</structfield></entry>
|
|
<entry><type>regproc</type></entry>
|
|
<entry><literal><link linkend="catalog-pg-proc"><structname>pg_proc</structname></link>.oid</literal></entry>
|
|
<entry><quote>Restore marked scan position</quote> function</entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry><structfield>ambuild</structfield></entry>
|
|
<entry><type>regproc</type></entry>
|
|
<entry><literal><link linkend="catalog-pg-proc"><structname>pg_proc</structname></link>.oid</literal></entry>
|
|
<entry><quote>Build new index</quote> function</entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry><structfield>ambulkdelete</structfield></entry>
|
|
<entry><type>regproc</type></entry>
|
|
<entry><literal><link linkend="catalog-pg-proc"><structname>pg_proc</structname></link>.oid</literal></entry>
|
|
<entry>Bulk-delete function</entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry><structfield>amvacuumcleanup</structfield></entry>
|
|
<entry><type>regproc</type></entry>
|
|
<entry><literal><link linkend="catalog-pg-proc"><structname>pg_proc</structname></link>.oid</literal></entry>
|
|
<entry>Post-<command>VACUUM</command> cleanup function</entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry><structfield>amcostestimate</structfield></entry>
|
|
<entry><type>regproc</type></entry>
|
|
<entry><literal><link linkend="catalog-pg-proc"><structname>pg_proc</structname></link>.oid</literal></entry>
|
|
<entry>Function to estimate cost of an index scan</entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry><structfield>amoptions</structfield></entry>
|
|
<entry><type>regproc</type></entry>
|
|
<entry><literal><link linkend="catalog-pg-proc"><structname>pg_proc</structname></link>.oid</literal></entry>
|
|
<entry>Function to parse and validate <structfield>reloptions</> for an index</entry>
|
|
</row>
|
|
|
|
</tbody>
|
|
</tgroup>
|
|
</table>
|
|
|
|
</sect1>
|
|
|
|
|
|
<sect1 id="catalog-pg-amop">
|
|
<title><structname>pg_amop</structname></title>
|
|
|
|
<indexterm zone="catalog-pg-amop">
|
|
<primary>pg_amop</primary>
|
|
</indexterm>
|
|
|
|
<para>
|
|
The catalog <structname>pg_amop</structname> stores information about
|
|
operators associated with access method operator families. There is one
|
|
row for each operator that is a member of an operator family. An operator
|
|
can appear in more than one family, but cannot appear in more than one
|
|
position within a family.
|
|
</para>
|
|
|
|
<table>
|
|
<title><structname>pg_amop</> Columns</title>
|
|
|
|
<tgroup cols="4">
|
|
<thead>
|
|
<row>
|
|
<entry>Name</entry>
|
|
<entry>Type</entry>
|
|
<entry>References</entry>
|
|
<entry>Description</entry>
|
|
</row>
|
|
</thead>
|
|
<tbody>
|
|
|
|
<row>
|
|
<entry><structfield>amopfamily</structfield></entry>
|
|
<entry><type>oid</type></entry>
|
|
<entry><literal><link linkend="catalog-pg-opfamily"><structname>pg_opfamily</structname></link>.oid</literal></entry>
|
|
<entry>The operator family this entry is for</entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry><structfield>amoplefttype</structfield></entry>
|
|
<entry><type>oid</type></entry>
|
|
<entry><literal><link linkend="catalog-pg-type"><structname>pg_type</structname></link>.oid</literal></entry>
|
|
<entry>Left-hand input data type of operator</entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry><structfield>amoprighttype</structfield></entry>
|
|
<entry><type>oid</type></entry>
|
|
<entry><literal><link linkend="catalog-pg-type"><structname>pg_type</structname></link>.oid</literal></entry>
|
|
<entry>Right-hand input data type of operator</entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry><structfield>amopstrategy</structfield></entry>
|
|
<entry><type>int2</type></entry>
|
|
<entry></entry>
|
|
<entry>Operator strategy number</entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry><structfield>amopopr</structfield></entry>
|
|
<entry><type>oid</type></entry>
|
|
<entry><literal><link linkend="catalog-pg-operator"><structname>pg_operator</structname></link>.oid</literal></entry>
|
|
<entry>OID of the operator</entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry><structfield>amopmethod</structfield></entry>
|
|
<entry><type>oid</type></entry>
|
|
<entry><literal><link linkend="catalog-pg-am"><structname>pg_am</structname></link>.oid</literal></entry>
|
|
<entry>Index access method operator family is for</entry>
|
|
</row>
|
|
|
|
</tbody>
|
|
</tgroup>
|
|
</table>
|
|
|
|
<para>
|
|
An entry's <structfield>amopmethod</> must match the
|
|
<structname>opfmethod</> of its containing operator family (including
|
|
<structfield>amopmethod</> here is an intentional denormalization of the
|
|
catalog structure for performance reasons). Also,
|
|
<structfield>amoplefttype</> and <structfield>amoprighttype</> must match
|
|
the <structfield>oprleft</> and <structfield>oprright</> fields of the
|
|
referenced <structname>pg_operator</> entry.
|
|
</para>
|
|
|
|
</sect1>
|
|
|
|
|
|
<sect1 id="catalog-pg-amproc">
|
|
<title><structname>pg_amproc</structname></title>
|
|
|
|
<indexterm zone="catalog-pg-amproc">
|
|
<primary>pg_amproc</primary>
|
|
</indexterm>
|
|
|
|
<para>
|
|
The catalog <structname>pg_amproc</structname> stores information about
|
|
support procedures associated with access method operator families. There
|
|
is one row for each support procedure belonging to an operator family.
|
|
</para>
|
|
|
|
<table>
|
|
<title><structname>pg_amproc</structname> Columns</title>
|
|
|
|
<tgroup cols="4">
|
|
<thead>
|
|
<row>
|
|
<entry>Name</entry>
|
|
<entry>Type</entry>
|
|
<entry>References</entry>
|
|
<entry>Description</entry>
|
|
</row>
|
|
</thead>
|
|
<tbody>
|
|
|
|
<row>
|
|
<entry><structfield>amprocfamily</structfield></entry>
|
|
<entry><type>oid</type></entry>
|
|
<entry><literal><link linkend="catalog-pg-opfamily"><structname>pg_opfamily</structname></link>.oid</literal></entry>
|
|
<entry>The operator family this entry is for</entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry><structfield>amproclefttype</structfield></entry>
|
|
<entry><type>oid</type></entry>
|
|
<entry><literal><link linkend="catalog-pg-type"><structname>pg_type</structname></link>.oid</literal></entry>
|
|
<entry>Left-hand input data type of associated operator</entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry><structfield>amprocrighttype</structfield></entry>
|
|
<entry><type>oid</type></entry>
|
|
<entry><literal><link linkend="catalog-pg-type"><structname>pg_type</structname></link>.oid</literal></entry>
|
|
<entry>Right-hand input data type of associated operator</entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry><structfield>amprocnum</structfield></entry>
|
|
<entry><type>int2</type></entry>
|
|
<entry></entry>
|
|
<entry>Support procedure number</entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry><structfield>amproc</structfield></entry>
|
|
<entry><type>regproc</type></entry>
|
|
<entry><literal><link linkend="catalog-pg-proc"><structname>pg_proc</structname></link>.oid</literal></entry>
|
|
<entry>OID of the procedure</entry>
|
|
</row>
|
|
|
|
</tbody>
|
|
</tgroup>
|
|
</table>
|
|
|
|
<para>
|
|
The usual interpretation of the
|
|
<structfield>amproclefttype</> and <structfield>amprocrighttype</> fields
|
|
is that they identify the left and right input types of the operator(s)
|
|
that a particular support procedure supports. For some access methods
|
|
these match the input data type(s) of the support procedure itself, for
|
|
others not. There is a notion of <quote>default</> support procedures for
|
|
an index, which are those with <structfield>amproclefttype</> and
|
|
<structfield>amprocrighttype</> both equal to the index opclass's
|
|
<structfield>opcintype</>.
|
|
</para>
|
|
|
|
</sect1>
|
|
|
|
|
|
<sect1 id="catalog-pg-attrdef">
|
|
<title><structname>pg_attrdef</structname></title>
|
|
|
|
<indexterm zone="catalog-pg-attrdef">
|
|
<primary>pg_attrdef</primary>
|
|
</indexterm>
|
|
|
|
<para>
|
|
The catalog <structname>pg_attrdef</structname> stores column default values. The main information
|
|
about columns is stored in <structname>pg_attribute</structname>
|
|
(see below). Only columns that explicitly specify a default value
|
|
(when the table is created or the column is added) will have an
|
|
entry here.
|
|
</para>
|
|
|
|
<table>
|
|
<title><structname>pg_attrdef</> Columns</title>
|
|
|
|
<tgroup cols="4">
|
|
<thead>
|
|
<row>
|
|
<entry>Name</entry>
|
|
<entry>Type</entry>
|
|
<entry>References</entry>
|
|
<entry>Description</entry>
|
|
</row>
|
|
</thead>
|
|
|
|
<tbody>
|
|
<row>
|
|
<entry><structfield>adrelid</structfield></entry>
|
|
<entry><type>oid</type></entry>
|
|
<entry><literal><link linkend="catalog-pg-class"><structname>pg_class</structname></link>.oid</literal></entry>
|
|
<entry>The table this column belongs to</entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry><structfield>adnum</structfield></entry>
|
|
<entry><type>int2</type></entry>
|
|
<entry><literal><link linkend="catalog-pg-attribute"><structname>pg_attribute</structname></link>.attnum</literal></entry>
|
|
<entry>The number of the column</entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry><structfield>adbin</structfield></entry>
|
|
<entry><type>text</type></entry>
|
|
<entry></entry>
|
|
<entry>The internal representation of the column default value</entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry><structfield>adsrc</structfield></entry>
|
|
<entry><type>text</type></entry>
|
|
<entry></entry>
|
|
<entry>A human-readable representation of the default value</entry>
|
|
</row>
|
|
</tbody>
|
|
</tgroup>
|
|
</table>
|
|
|
|
<para>
|
|
The <structfield>adsrc</structfield> field is historical, and is best
|
|
not used, because it does not track outside changes that might affect
|
|
the representation of the default value. Reverse-compiling the
|
|
<structfield>adbin</structfield> field (with <function>pg_get_expr</> for
|
|
example) is a better way to display the default value.
|
|
</para>
|
|
|
|
</sect1>
|
|
|
|
|
|
<sect1 id="catalog-pg-attribute">
|
|
<title><structname>pg_attribute</structname></title>
|
|
|
|
<indexterm zone="catalog-pg-attribute">
|
|
<primary>pg_attribute</primary>
|
|
</indexterm>
|
|
|
|
<para>
|
|
The catalog <structname>pg_attribute</structname> stores information about
|
|
table columns. There will be exactly one
|
|
<structname>pg_attribute</structname> row for every column in every
|
|
table in the database. (There will also be attribute entries for
|
|
indexes, and indeed all objects that have <structname>pg_class</structname>
|
|
entries.)
|
|
</para>
|
|
|
|
<para>
|
|
The term attribute is equivalent to column and is used for
|
|
historical reasons.
|
|
</para>
|
|
|
|
<table>
|
|
<title><structname>pg_attribute</> Columns</title>
|
|
|
|
<tgroup cols="4">
|
|
<thead>
|
|
<row>
|
|
<entry>Name</entry>
|
|
<entry>Type</entry>
|
|
<entry>References</entry>
|
|
<entry>Description</entry>
|
|
</row>
|
|
</thead>
|
|
|
|
<tbody>
|
|
<row>
|
|
<entry><structfield>attrelid</structfield></entry>
|
|
<entry><type>oid</type></entry>
|
|
<entry><literal><link linkend="catalog-pg-class"><structname>pg_class</structname></link>.oid</literal></entry>
|
|
<entry>The table this column belongs to</entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry><structfield>attname</structfield></entry>
|
|
<entry><type>name</type></entry>
|
|
<entry></entry>
|
|
<entry>The column name</entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry><structfield>atttypid</structfield></entry>
|
|
<entry><type>oid</type></entry>
|
|
<entry><literal><link linkend="catalog-pg-type"><structname>pg_type</structname></link>.oid</literal></entry>
|
|
<entry>The data type of this column</entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry><structfield>attstattarget</structfield></entry>
|
|
<entry><type>int4</type></entry>
|
|
<entry></entry>
|
|
<entry>
|
|
<structfield>attstattarget</structfield> controls the level of detail
|
|
of statistics accumulated for this column by
|
|
<xref linkend="sql-analyze" endterm="sql-analyze-title">.
|
|
A zero value indicates that no statistics should be collected.
|
|
A negative value says to use the system default statistics target.
|
|
The exact meaning of positive values is data type-dependent.
|
|
For scalar data types, <structfield>attstattarget</structfield>
|
|
is both the target number of <quote>most common values</quote>
|
|
to collect, and the target number of histogram bins to create
|
|
</entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry><structfield>attdistinct</structfield></entry>
|
|
<entry><type>float4</type></entry>
|
|
<entry></entry>
|
|
<entry>
|
|
<structfield>attdistinct</structfield>, if nonzero, is a user-specified
|
|
number-of-distinct-values figure to be used instead of estimating the
|
|
number of distinct values during <command>ANALYZE</>. Nonzero values
|
|
have the same meanings as for
|
|
<link linkend="catalog-pg-statistic"><structname>pg_statistic</></link>.<structfield>stadistinct</>
|
|
</entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry><structfield>attlen</structfield></entry>
|
|
<entry><type>int2</type></entry>
|
|
<entry></entry>
|
|
<entry>
|
|
A copy of <literal>pg_type.typlen</literal> of this column's
|
|
type
|
|
</entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry><structfield>attnum</structfield></entry>
|
|
<entry><type>int2</type></entry>
|
|
<entry></entry>
|
|
<entry>
|
|
The number of the column. Ordinary columns are numbered from 1
|
|
up. System columns, such as <structfield>oid</structfield>,
|
|
have (arbitrary) negative numbers
|
|
</entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry><structfield>attndims</structfield></entry>
|
|
<entry><type>int4</type></entry>
|
|
<entry></entry>
|
|
<entry>
|
|
Number of dimensions, if the column is an array type; otherwise 0.
|
|
(Presently, the number of dimensions of an array is not enforced,
|
|
so any nonzero value effectively means <quote>it's an array</>)
|
|
</entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry><structfield>attcacheoff</structfield></entry>
|
|
<entry><type>int4</type></entry>
|
|
<entry></entry>
|
|
<entry>
|
|
Always -1 in storage, but when loaded into a row descriptor
|
|
in memory this might be updated to cache the offset of the attribute
|
|
within the row
|
|
</entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry><structfield>atttypmod</structfield></entry>
|
|
<entry><type>int4</type></entry>
|
|
<entry></entry>
|
|
<entry>
|
|
<structfield>atttypmod</structfield> records type-specific data
|
|
supplied at table creation time (for example, the maximum
|
|
length of a <type>varchar</type> column). It is passed to
|
|
type-specific input functions and length coercion functions.
|
|
The value will generally be -1 for types that do not need <structfield>atttypmod</>
|
|
</entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry><structfield>attbyval</structfield></entry>
|
|
<entry><type>bool</type></entry>
|
|
<entry></entry>
|
|
<entry>
|
|
A copy of <literal>pg_type.typbyval</> of this column's type
|
|
</entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry><structfield>attstorage</structfield></entry>
|
|
<entry><type>char</type></entry>
|
|
<entry></entry>
|
|
<entry>
|
|
Normally a copy of <literal>pg_type.typstorage</> of this
|
|
column's type. For TOAST-able data types, this can be altered
|
|
after column creation to control storage policy
|
|
</entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry><structfield>attalign</structfield></entry>
|
|
<entry><type>char</type></entry>
|
|
<entry></entry>
|
|
<entry>
|
|
A copy of <literal>pg_type.typalign</> of this column's type
|
|
</entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry><structfield>attnotnull</structfield></entry>
|
|
<entry><type>bool</type></entry>
|
|
<entry></entry>
|
|
<entry>
|
|
This represents a not-null constraint. It is possible to
|
|
change this column to enable or disable the constraint
|
|
</entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry><structfield>atthasdef</structfield></entry>
|
|
<entry><type>bool</type></entry>
|
|
<entry></entry>
|
|
<entry>
|
|
This column has a default value, in which case there will be a
|
|
corresponding entry in the <structname>pg_attrdef</structname>
|
|
catalog that actually defines the value
|
|
</entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry><structfield>attisdropped</structfield></entry>
|
|
<entry><type>bool</type></entry>
|
|
<entry></entry>
|
|
<entry>
|
|
This column has been dropped and is no longer valid. A dropped
|
|
column is still physically present in the table, but is
|
|
ignored by the parser and so cannot be accessed via SQL
|
|
</entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry><structfield>attislocal</structfield></entry>
|
|
<entry><type>bool</type></entry>
|
|
<entry></entry>
|
|
<entry>
|
|
This column is defined locally in the relation. Note that a column can
|
|
be locally defined and inherited simultaneously
|
|
</entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry><structfield>attinhcount</structfield></entry>
|
|
<entry><type>int4</type></entry>
|
|
<entry></entry>
|
|
<entry>
|
|
The number of direct ancestors this column has. A column with a
|
|
nonzero number of ancestors cannot be dropped nor renamed
|
|
</entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry><structfield>attacl</structfield></entry>
|
|
<entry><type>aclitem[]</type></entry>
|
|
<entry></entry>
|
|
<entry>
|
|
Column-level access privileges, if any have been granted specifically
|
|
on this column
|
|
</entry>
|
|
</row>
|
|
|
|
</tbody>
|
|
</tgroup>
|
|
</table>
|
|
|
|
<para>
|
|
In a dropped column's <structname>pg_attribute</structname> entry,
|
|
<structfield>atttypid</structfield> is reset to zero, but
|
|
<structfield>attlen</structfield> and the other fields copied from
|
|
<structname>pg_type</> are still valid. This arrangement is needed
|
|
to cope with the situation where the dropped column's data type was
|
|
later dropped, and so there is no <structname>pg_type</> row anymore.
|
|
<structfield>attlen</structfield> and the other fields can be used
|
|
to interpret the contents of a row of the table.
|
|
</para>
|
|
</sect1>
|
|
|
|
|
|
<sect1 id="catalog-pg-authid">
|
|
<title><structname>pg_authid</structname></title>
|
|
|
|
<indexterm zone="catalog-pg-authid">
|
|
<primary>pg_authid</primary>
|
|
</indexterm>
|
|
|
|
<para>
|
|
The catalog <structname>pg_authid</structname> contains information about
|
|
database authorization identifiers (roles). A role subsumes the concepts
|
|
of <quote>users</> and <quote>groups</>. A user is essentially just a
|
|
role with the <structfield>rolcanlogin</> flag set. Any role (with or
|
|
without <structfield>rolcanlogin</>) can have other roles as members; see
|
|
<link linkend="catalog-pg-auth-members"><structname>pg_auth_members</structname></link>.
|
|
</para>
|
|
|
|
<para>
|
|
Since this catalog contains passwords, it must not be publicly readable.
|
|
<link linkend="view-pg-roles"><structname>pg_roles</structname></link>
|
|
is a publicly readable view on
|
|
<structname>pg_authid</structname> that blanks out the password field.
|
|
</para>
|
|
|
|
<para>
|
|
<xref linkend="user-manag"> contains detailed information about user and
|
|
privilege management.
|
|
</para>
|
|
|
|
<para>
|
|
Because user identities are cluster-wide,
|
|
<structname>pg_authid</structname>
|
|
is shared across all databases of a cluster: there is only one
|
|
copy of <structname>pg_authid</structname> per cluster, not
|
|
one per database.
|
|
</para>
|
|
|
|
<table>
|
|
<title><structname>pg_authid</> Columns</title>
|
|
|
|
<tgroup cols="3">
|
|
<thead>
|
|
<row>
|
|
<entry>Name</entry>
|
|
<entry>Type</entry>
|
|
<entry>Description</entry>
|
|
</row>
|
|
</thead>
|
|
|
|
<tbody>
|
|
<row>
|
|
<entry><structfield>rolname</structfield></entry>
|
|
<entry><type>name</type></entry>
|
|
<entry>Role name</entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry><structfield>rolsuper</structfield></entry>
|
|
<entry><type>bool</type></entry>
|
|
<entry>Role has superuser privileges</entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry><structfield>rolinherit</structfield></entry>
|
|
<entry><type>bool</type></entry>
|
|
<entry>Role automatically inherits privileges of roles it is a
|
|
member of</entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry><structfield>rolcreaterole</structfield></entry>
|
|
<entry><type>bool</type></entry>
|
|
<entry>Role can create more roles</entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry><structfield>rolcreatedb</structfield></entry>
|
|
<entry><type>bool</type></entry>
|
|
<entry>Role can create databases</entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry><structfield>rolcatupdate</structfield></entry>
|
|
<entry><type>bool</type></entry>
|
|
<entry>
|
|
Role can update system catalogs directly. (Even a superuser cannot do
|
|
this unless this column is true)
|
|
</entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry><structfield>rolcanlogin</structfield></entry>
|
|
<entry><type>bool</type></entry>
|
|
<entry>
|
|
Role can log in. That is, this role can be given as the initial
|
|
session authorization identifier
|
|
</entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry><structfield>rolconnlimit</structfield></entry>
|
|
<entry><type>int4</type></entry>
|
|
<entry>
|
|
For roles that can log in, this sets maximum number of concurrent
|
|
connections this role can make. -1 means no limit
|
|
</entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry><structfield>rolpassword</structfield></entry>
|
|
<entry><type>text</type></entry>
|
|
<entry>Password (possibly encrypted); NULL if none</entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry><structfield>rolvaliduntil</structfield></entry>
|
|
<entry><type>timestamptz</type></entry>
|
|
<entry>Password expiry time (only used for password authentication);
|
|
NULL if no expiration</entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry><structfield>rolconfig</structfield></entry>
|
|
<entry><type>text[]</type></entry>
|
|
<entry>Session defaults for run-time configuration variables</entry>
|
|
</row>
|
|
</tbody>
|
|
</tgroup>
|
|
</table>
|
|
|
|
</sect1>
|
|
|
|
|
|
<sect1 id="catalog-pg-auth-members">
|
|
<title><structname>pg_auth_members</structname></title>
|
|
|
|
<indexterm zone="catalog-pg-auth-members">
|
|
<primary>pg_auth_members</primary>
|
|
</indexterm>
|
|
|
|
<para>
|
|
The catalog <structname>pg_auth_members</structname> shows the membership
|
|
relations between roles. Any non-circular set of relationships is allowed.
|
|
</para>
|
|
|
|
<para>
|
|
Because user identities are cluster-wide,
|
|
<structname>pg_auth_members</structname>
|
|
is shared across all databases of a cluster: there is only one
|
|
copy of <structname>pg_auth_members</structname> per cluster, not
|
|
one per database.
|
|
</para>
|
|
|
|
<table>
|
|
<title><structname>pg_auth_members</> Columns</title>
|
|
|
|
<tgroup cols="4">
|
|
<thead>
|
|
<row>
|
|
<entry>Name</entry>
|
|
<entry>Type</entry>
|
|
<entry>References</entry>
|
|
<entry>Description</entry>
|
|
</row>
|
|
</thead>
|
|
|
|
<tbody>
|
|
<row>
|
|
<entry><structfield>roleid</structfield></entry>
|
|
<entry><type>oid</type></entry>
|
|
<entry><literal><link linkend="catalog-pg-authid"><structname>pg_authid</structname></link>.oid</literal></entry>
|
|
<entry>ID of a role that has a member</entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry><structfield>member</structfield></entry>
|
|
<entry><type>oid</type></entry>
|
|
<entry><literal><link linkend="catalog-pg-authid"><structname>pg_authid</structname></link>.oid</literal></entry>
|
|
<entry>ID of a role that is a member of <structfield>roleid</></entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry><structfield>grantor</structfield></entry>
|
|
<entry><type>oid</type></entry>
|
|
<entry><literal><link linkend="catalog-pg-authid"><structname>pg_authid</structname></link>.oid</literal></entry>
|
|
<entry>ID of the role that granted this membership</entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry><structfield>admin_option</structfield></entry>
|
|
<entry><type>bool</type></entry>
|
|
<entry></entry>
|
|
<entry>True if <structfield>member</> can grant membership in
|
|
<structfield>roleid</> to others</entry>
|
|
</row>
|
|
</tbody>
|
|
</tgroup>
|
|
</table>
|
|
|
|
</sect1>
|
|
|
|
|
|
<sect1 id="catalog-pg-cast">
|
|
<title><structname>pg_cast</structname></title>
|
|
|
|
<indexterm zone="catalog-pg-cast">
|
|
<primary>pg_cast</primary>
|
|
</indexterm>
|
|
|
|
<para>
|
|
The catalog <structname>pg_cast</structname> stores data type conversion
|
|
paths, both built-in paths and those defined with
|
|
<xref linkend="sql-createcast" endterm="sql-createcast-title">.
|
|
</para>
|
|
|
|
<para>
|
|
It should be noted that <structname>pg_cast</structname> does not represent
|
|
every type conversion that the system knows how to perform; only those that
|
|
cannot be deduced from some generic rule. For example, casting between a
|
|
domain and its base type is not explicitly represented in
|
|
<structname>pg_cast</structname>. Another important exception is that
|
|
<quote>automatic I/O conversion casts</>, those performed using a data
|
|
type's own I/O functions to convert to or from <type>text</> or other
|
|
string types, are not explicitly represented in
|
|
<structname>pg_cast</structname>.
|
|
</para>
|
|
|
|
<table>
|
|
<title><structname>pg_cast</> Columns</title>
|
|
|
|
<tgroup cols="4">
|
|
<thead>
|
|
<row>
|
|
<entry>Name</entry>
|
|
<entry>Type</entry>
|
|
<entry>References</entry>
|
|
<entry>Description</entry>
|
|
</row>
|
|
</thead>
|
|
|
|
<tbody>
|
|
<row>
|
|
<entry><structfield>castsource</structfield></entry>
|
|
<entry><type>oid</type></entry>
|
|
<entry><literal><link linkend="catalog-pg-type"><structname>pg_type</structname></link>.oid</literal></entry>
|
|
<entry>OID of the source data type</entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry><structfield>casttarget</structfield></entry>
|
|
<entry><type>oid</type></entry>
|
|
<entry><literal><link linkend="catalog-pg-type"><structname>pg_type</structname></link>.oid</literal></entry>
|
|
<entry>OID of the target data type</entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry><structfield>castfunc</structfield></entry>
|
|
<entry><type>oid</type></entry>
|
|
<entry><literal><link linkend="catalog-pg-proc"><structname>pg_proc</structname></link>.oid</literal></entry>
|
|
<entry>
|
|
The OID of the function to use to perform this cast. Zero is
|
|
stored if the cast method doesn't require a function.
|
|
</entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry><structfield>castcontext</structfield></entry>
|
|
<entry><type>char</type></entry>
|
|
<entry></entry>
|
|
<entry>
|
|
Indicates what contexts the cast can be invoked in.
|
|
<literal>e</> means only as an explicit cast (using
|
|
<literal>CAST</> or <literal>::</> syntax).
|
|
<literal>a</> means implicitly in assignment
|
|
to a target column, as well as explicitly.
|
|
<literal>i</> means implicitly in expressions, as well as the
|
|
other cases
|
|
</entry>
|
|
</row>
|
|
<row>
|
|
<entry><structfield>castmethod</structfield></entry>
|
|
<entry><type>char</type></entry>
|
|
<entry></entry>
|
|
<entry>
|
|
Indicates how the cast is performed.
|
|
<literal>f</> means that the function specified in the <structfield>castfunc</> field is used.
|
|
<literal>i</> means that the input/output functions are used.
|
|
<literal>b</> means that the types are binary-coercible, thus no conversion is required
|
|
</entry>
|
|
</row>
|
|
</tbody>
|
|
</tgroup>
|
|
</table>
|
|
|
|
<para>
|
|
The cast functions listed in <structname>pg_cast</structname> must
|
|
always take the cast source type as their first argument type, and
|
|
return the cast destination type as their result type. A cast
|
|
function can have up to three arguments. The second argument,
|
|
if present, must be type <type>integer</>; it receives the type
|
|
modifier associated with the destination type, or <literal>-1</>
|
|
if there is none. The third argument,
|
|
if present, must be type <type>boolean</>; it receives <literal>true</>
|
|
if the cast is an explicit cast, <literal>false</> otherwise.
|
|
</para>
|
|
|
|
<para>
|
|
It is legitimate to create a <structname>pg_cast</structname> entry
|
|
in which the source and target types are the same, if the associated
|
|
function takes more than one argument. Such entries represent
|
|
<quote>length coercion functions</> that coerce values of the type
|
|
to be legal for a particular type modifier value.
|
|
</para>
|
|
|
|
<para>
|
|
When a <structname>pg_cast</structname> entry has different source and
|
|
target types and a function that takes more than one argument, it
|
|
represents converting from one type to another and applying a length
|
|
coercion in a single step. When no such entry is available, coercion
|
|
to a type that uses a type modifier involves two steps, one to
|
|
convert between data types and a second to apply the modifier.
|
|
</para>
|
|
</sect1>
|
|
|
|
<sect1 id="catalog-pg-class">
|
|
<title><structname>pg_class</structname></title>
|
|
|
|
<indexterm zone="catalog-pg-class">
|
|
<primary>pg_class</primary>
|
|
</indexterm>
|
|
|
|
<para>
|
|
The catalog <structname>pg_class</structname> catalogs tables and most
|
|
everything else that has columns or is otherwise similar to a
|
|
table. This includes indexes (but see also
|
|
<structname>pg_index</structname>), sequences, views, composite types,
|
|
and TOAST tables; see <structfield>relkind</>.
|
|
Below, when we mean all of these
|
|
kinds of objects we speak of <quote>relations</quote>. Not all
|
|
columns are meaningful for all relation types.
|
|
</para>
|
|
|
|
<table>
|
|
<title><structname>pg_class</> Columns</title>
|
|
|
|
<tgroup cols="4">
|
|
<thead>
|
|
<row>
|
|
<entry>Name</entry>
|
|
<entry>Type</entry>
|
|
<entry>References</entry>
|
|
<entry>Description</entry>
|
|
</row>
|
|
</thead>
|
|
|
|
<tbody>
|
|
<row>
|
|
<entry><structfield>relname</structfield></entry>
|
|
<entry><type>name</type></entry>
|
|
<entry></entry>
|
|
<entry>Name of the table, index, view, etc.</entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry><structfield>relnamespace</structfield></entry>
|
|
<entry><type>oid</type></entry>
|
|
<entry><literal><link linkend="catalog-pg-namespace"><structname>pg_namespace</structname></link>.oid</literal></entry>
|
|
<entry>
|
|
The OID of the namespace that contains this relation
|
|
</entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry><structfield>reltype</structfield></entry>
|
|
<entry><type>oid</type></entry>
|
|
<entry><literal><link linkend="catalog-pg-type"><structname>pg_type</structname></link>.oid</literal></entry>
|
|
<entry>
|
|
The OID of the data type that corresponds to this table's row type,
|
|
if any (zero for indexes, which have no <structname>pg_type</> entry)
|
|
</entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry><structfield>relowner</structfield></entry>
|
|
<entry><type>oid</type></entry>
|
|
<entry><literal><link linkend="catalog-pg-authid"><structname>pg_authid</structname></link>.oid</literal></entry>
|
|
<entry>Owner of the relation</entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry><structfield>relam</structfield></entry>
|
|
<entry><type>oid</type></entry>
|
|
<entry><literal><link linkend="catalog-pg-am"><structname>pg_am</structname></link>.oid</literal></entry>
|
|
<entry>If this is an index, the access method used (B-tree, hash, etc.)</entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry><structfield>relfilenode</structfield></entry>
|
|
<entry><type>oid</type></entry>
|
|
<entry></entry>
|
|
<entry>Name of the on-disk file of this relation; 0 if none</entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry><structfield>reltablespace</structfield></entry>
|
|
<entry><type>oid</type></entry>
|
|
<entry><literal><link linkend="catalog-pg-tablespace"><structname>pg_tablespace</structname></link>.oid</literal></entry>
|
|
<entry>
|
|
The tablespace in which this relation is stored. If zero,
|
|
the database's default tablespace is implied. (Not meaningful
|
|
if the relation has no on-disk file.)
|
|
</entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry><structfield>relpages</structfield></entry>
|
|
<entry><type>int4</type></entry>
|
|
<entry></entry>
|
|
<entry>
|
|
Size of the on-disk representation of this table in pages (of size
|
|
<symbol>BLCKSZ</symbol>). This is only an estimate used by the
|
|
planner. It is updated by <command>VACUUM</command>,
|
|
<command>ANALYZE</command>, and a few DDL commands such as
|
|
<command>CREATE INDEX</command>
|
|
</entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry><structfield>reltuples</structfield></entry>
|
|
<entry><type>float4</type></entry>
|
|
<entry></entry>
|
|
<entry>
|
|
Number of rows in the table. This is only an estimate used by the
|
|
planner. It is updated by <command>VACUUM</command>,
|
|
<command>ANALYZE</command>, and a few DDL commands such as
|
|
<command>CREATE INDEX</command>
|
|
</entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry><structfield>reltoastrelid</structfield></entry>
|
|
<entry><type>oid</type></entry>
|
|
<entry><literal><link linkend="catalog-pg-class"><structname>pg_class</structname></link>.oid</literal></entry>
|
|
<entry>
|
|
OID of the TOAST table associated with this table, 0 if none. The
|
|
TOAST table stores large attributes <quote>out of line</quote> in a
|
|
secondary table
|
|
</entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry><structfield>reltoastidxid</structfield></entry>
|
|
<entry><type>oid</type></entry>
|
|
<entry><literal><link linkend="catalog-pg-class"><structname>pg_class</structname></link>.oid</literal></entry>
|
|
<entry>
|
|
For a TOAST table, the OID of its index. 0 if not a TOAST table
|
|
</entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry><structfield>relhasindex</structfield></entry>
|
|
<entry><type>bool</type></entry>
|
|
<entry></entry>
|
|
<entry>
|
|
True if this is a table and it has (or recently had) any indexes
|
|
</entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry><structfield>relisshared</structfield></entry>
|
|
<entry><type>bool</type></entry>
|
|
<entry></entry>
|
|
<entry>
|
|
True if this table is shared across all databases in the cluster. Only
|
|
certain system catalogs (such as <structname>pg_database</structname>)
|
|
are shared
|
|
</entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry><structfield>relistemp</structfield></entry>
|
|
<entry><type>bool</type></entry>
|
|
<entry></entry>
|
|
<entry>
|
|
True if this table is a temporary relation. If so, only the creating
|
|
session can safely access its contents
|
|
</entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry><structfield>relkind</structfield></entry>
|
|
<entry><type>char</type></entry>
|
|
<entry></entry>
|
|
<entry>
|
|
<literal>r</> = ordinary table, <literal>i</> = index,
|
|
<literal>S</> = sequence, <literal>v</> = view, <literal>c</> =
|
|
composite type, <literal>t</> = TOAST
|
|
table
|
|
</entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry><structfield>relnatts</structfield></entry>
|
|
<entry><type>int2</type></entry>
|
|
<entry></entry>
|
|
<entry>
|
|
Number of user columns in the relation (system columns not
|
|
counted). There must be this many corresponding entries in
|
|
<structname>pg_attribute</structname>. See also
|
|
<literal>pg_attribute.attnum</literal>
|
|
</entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry><structfield>relchecks</structfield></entry>
|
|
<entry><type>int2</type></entry>
|
|
<entry></entry>
|
|
<entry>
|
|
Number of <literal>CHECK</> constraints on the table; see
|
|
<link linkend="catalog-pg-constraint"><structname>pg_constraint</structname></link> catalog
|
|
</entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry><structfield>relhasoids</structfield></entry>
|
|
<entry><type>bool</type></entry>
|
|
<entry></entry>
|
|
<entry>
|
|
True if we generate an OID for each row of the relation
|
|
</entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry><structfield>relhaspkey</structfield></entry>
|
|
<entry><type>bool</type></entry>
|
|
<entry></entry>
|
|
<entry>
|
|
True if the table has (or once had) a primary key
|
|
</entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry><structfield>relhasexclusion</structfield></entry>
|
|
<entry><type>bool</type></entry>
|
|
<entry></entry>
|
|
<entry>
|
|
For a table, true if the table has (or once had) any exclusion
|
|
constraints; for an index, true if the index supports an exclusion
|
|
constraint
|
|
</entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry><structfield>relhasrules</structfield></entry>
|
|
<entry><type>bool</type></entry>
|
|
<entry></entry>
|
|
<entry>
|
|
True if table has (or once had) rules; see
|
|
<link linkend="catalog-pg-rewrite"><structname>pg_rewrite</structname></link> catalog
|
|
</entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry><structfield>relhastriggers</structfield></entry>
|
|
<entry><type>bool</type></entry>
|
|
<entry></entry>
|
|
<entry>
|
|
True if table has (or once had) triggers; see
|
|
<link linkend="catalog-pg-trigger"><structname>pg_trigger</structname></link> catalog
|
|
</entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry><structfield>relhassubclass</structfield></entry>
|
|
<entry><type>bool</type></entry>
|
|
<entry></entry>
|
|
<entry>True if table has (or once had) any inheritance children</entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry><structfield>relfrozenxid</structfield></entry>
|
|
<entry><type>xid</type></entry>
|
|
<entry></entry>
|
|
<entry>
|
|
All transaction IDs before this one have been replaced with a permanent
|
|
(<quote>frozen</>) transaction ID in this table. This is used to track
|
|
whether the table needs to be vacuumed in order to prevent transaction
|
|
ID wraparound or to allow <literal>pg_clog</> to be shrunk. Zero
|
|
(<symbol>InvalidTransactionId</symbol>) if the relation is not a table
|
|
</entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry><structfield>relacl</structfield></entry>
|
|
<entry><type>aclitem[]</type></entry>
|
|
<entry></entry>
|
|
<entry>
|
|
Access privileges; see
|
|
<xref linkend="sql-grant" endterm="sql-grant-title"> and
|
|
<xref linkend="sql-revoke" endterm="sql-revoke-title">
|
|
for details
|
|
</entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry><structfield>reloptions</structfield></entry>
|
|
<entry><type>text[]</type></entry>
|
|
<entry></entry>
|
|
<entry>
|
|
Access-method-specific options, as <quote>keyword=value</> strings
|
|
</entry>
|
|
</row>
|
|
</tbody>
|
|
</tgroup>
|
|
</table>
|
|
|
|
<para>
|
|
Several of the boolean flags in <structname>pg_class</> are maintained
|
|
lazily: they are guaranteed to be true if that's the correct state, but
|
|
may not be reset to false immediately when the condition is no longer
|
|
true. For example, <structfield>relhasindex</> is set by
|
|
<command>CREATE INDEX</command>, but it is never cleared by
|
|
<command>DROP INDEX</command>. Instead, <command>VACUUM</command> clears
|
|
<structfield>relhasindex</> if it finds the table has no indexes. This
|
|
arrangement avoids race conditions and improves concurrency.
|
|
</para>
|
|
</sect1>
|
|
|
|
<sect1 id="catalog-pg-constraint">
|
|
<title><structname>pg_constraint</structname></title>
|
|
|
|
<indexterm zone="catalog-pg-constraint">
|
|
<primary>pg_constraint</primary>
|
|
</indexterm>
|
|
|
|
<para>
|
|
The catalog <structname>pg_constraint</structname> stores check, primary
|
|
key, unique, foreign key, and exclusion constraints on tables.
|
|
(Column constraints are not treated specially. Every column constraint is
|
|
equivalent to some table constraint.)
|
|
Not-null constraints are represented in the <structname>pg_attribute</>
|
|
catalog, not here.
|
|
</para>
|
|
|
|
<para>
|
|
Check constraints on domains are stored here, too.
|
|
</para>
|
|
|
|
<table>
|
|
<title><structname>pg_constraint</> Columns</title>
|
|
|
|
<tgroup cols="4">
|
|
<thead>
|
|
<row>
|
|
<entry>Name</entry>
|
|
<entry>Type</entry>
|
|
<entry>References</entry>
|
|
<entry>Description</entry>
|
|
</row>
|
|
</thead>
|
|
|
|
<tbody>
|
|
<row>
|
|
<entry><structfield>conname</structfield></entry>
|
|
<entry><type>name</type></entry>
|
|
<entry></entry>
|
|
<entry>Constraint name (not necessarily unique!)</entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry><structfield>connamespace</structfield></entry>
|
|
<entry><type>oid</type></entry>
|
|
<entry><literal><link linkend="catalog-pg-namespace"><structname>pg_namespace</structname></link>.oid</literal></entry>
|
|
<entry>
|
|
The OID of the namespace that contains this constraint
|
|
</entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry><structfield>contype</structfield></entry>
|
|
<entry><type>char</type></entry>
|
|
<entry></entry>
|
|
<entry>
|
|
<literal>c</> = check constraint,
|
|
<literal>f</> = foreign key constraint,
|
|
<literal>p</> = primary key constraint,
|
|
<literal>u</> = unique constraint,
|
|
<literal>x</> = exclusion constraint
|
|
</entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry><structfield>condeferrable</structfield></entry>
|
|
<entry><type>bool</type></entry>
|
|
<entry></entry>
|
|
<entry>Is the constraint deferrable?</entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry><structfield>condeferred</structfield></entry>
|
|
<entry><type>bool</type></entry>
|
|
<entry></entry>
|
|
<entry>Is the constraint deferred by default?</entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry><structfield>conrelid</structfield></entry>
|
|
<entry><type>oid</type></entry>
|
|
<entry><literal><link linkend="catalog-pg-class"><structname>pg_class</structname></link>.oid</literal></entry>
|
|
<entry>The table this constraint is on; 0 if not a table constraint</entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry><structfield>contypid</structfield></entry>
|
|
<entry><type>oid</type></entry>
|
|
<entry><literal><link linkend="catalog-pg-type"><structname>pg_type</structname></link>.oid</literal></entry>
|
|
<entry>The domain this constraint is on; 0 if not a domain constraint</entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry><structfield>conindid</structfield></entry>
|
|
<entry><type>oid</type></entry>
|
|
<entry><literal><link linkend="catalog-pg-class"><structname>pg_class</structname></link>.oid</literal></entry>
|
|
<entry>The index supporting this constraint, if it's a unique, primary
|
|
key, foreign key, or exclusion constraint; else 0</entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry><structfield>confrelid</structfield></entry>
|
|
<entry><type>oid</type></entry>
|
|
<entry><literal><link linkend="catalog-pg-class"><structname>pg_class</structname></link>.oid</literal></entry>
|
|
<entry>If a foreign key, the referenced table; else 0</entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry><structfield>confupdtype</structfield></entry>
|
|
<entry><type>char</type></entry>
|
|
<entry></entry>
|
|
<entry>Foreign key update action code:
|
|
<literal>a</> = no action,
|
|
<literal>r</> = restrict,
|
|
<literal>c</> = cascade,
|
|
<literal>n</> = set null,
|
|
<literal>d</> = set default
|
|
</entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry><structfield>confdeltype</structfield></entry>
|
|
<entry><type>char</type></entry>
|
|
<entry></entry>
|
|
<entry>Foreign key deletion action code:
|
|
<literal>a</> = no action,
|
|
<literal>r</> = restrict,
|
|
<literal>c</> = cascade,
|
|
<literal>n</> = set null,
|
|
<literal>d</> = set default
|
|
</entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry><structfield>confmatchtype</structfield></entry>
|
|
<entry><type>char</type></entry>
|
|
<entry></entry>
|
|
<entry>Foreign key match type:
|
|
<literal>f</> = full,
|
|
<literal>p</> = partial,
|
|
<literal>u</> = simple (unspecified)
|
|
</entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry><structfield>conislocal</structfield></entry>
|
|
<entry><type>bool</type></entry>
|
|
<entry></entry>
|
|
<entry>
|
|
This constraint is defined locally for the relation. Note that a
|
|
constraint can be locally defined and inherited simultaneously
|
|
</entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry><structfield>coninhcount</structfield></entry>
|
|
<entry><type>int4</type></entry>
|
|
<entry></entry>
|
|
<entry>
|
|
The number of direct inheritance ancestors this constraint has.
|
|
A constraint with
|
|
a nonzero number of ancestors cannot be dropped nor renamed
|
|
</entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry><structfield>conkey</structfield></entry>
|
|
<entry><type>int2[]</type></entry>
|
|
<entry><literal><link linkend="catalog-pg-attribute"><structname>pg_attribute</structname></link>.attnum</></entry>
|
|
<entry>If a table constraint (including a foreign key), list of the constrained columns</entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry><structfield>confkey</structfield></entry>
|
|
<entry><type>int2[]</type></entry>
|
|
<entry><literal><link linkend="catalog-pg-attribute"><structname>pg_attribute</structname></link>.attnum</></entry>
|
|
<entry>If a foreign key, list of the referenced columns</entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry><structfield>conpfeqop</structfield></entry>
|
|
<entry><type>oid[]</type></entry>
|
|
<entry><literal><link linkend="catalog-pg-operator"><structname>pg_operator</structname></link>.oid</></entry>
|
|
<entry>If a foreign key, list of the equality operators for PK = FK comparisons</entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry><structfield>conppeqop</structfield></entry>
|
|
<entry><type>oid[]</type></entry>
|
|
<entry><literal><link linkend="catalog-pg-operator"><structname>pg_operator</structname></link>.oid</></entry>
|
|
<entry>If a foreign key, list of the equality operators for PK = PK comparisons</entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry><structfield>conffeqop</structfield></entry>
|
|
<entry><type>oid[]</type></entry>
|
|
<entry><literal><link linkend="catalog-pg-operator"><structname>pg_operator</structname></link>.oid</></entry>
|
|
<entry>If a foreign key, list of the equality operators for FK = FK comparisons</entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry><structfield>conexclop</structfield></entry>
|
|
<entry><type>oid[]</type></entry>
|
|
<entry><literal><link linkend="catalog-pg-operator"><structname>pg_operator</structname></link>.oid</></entry>
|
|
<entry>If an exclusion constraint, list of the per-column exclusion operators</entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry><structfield>conbin</structfield></entry>
|
|
<entry><type>text</type></entry>
|
|
<entry></entry>
|
|
<entry>If a check constraint, an internal representation of the expression</entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry><structfield>consrc</structfield></entry>
|
|
<entry><type>text</type></entry>
|
|
<entry></entry>
|
|
<entry>If a check constraint, a human-readable representation of the expression</entry>
|
|
</row>
|
|
</tbody>
|
|
</tgroup>
|
|
</table>
|
|
|
|
<para>
|
|
In the case of an exclusion constraint, <structfield>conkey</structfield>
|
|
is only useful for constraint elements that are simple column references.
|
|
For other cases, a zero appears in <structfield>conkey</structfield>
|
|
and the associated index must be consulted to discover the expression
|
|
that is constrained. (<structfield>conkey</structfield> thus has the
|
|
same contents as <structname>pg_index</>.<structfield>indkey</> for the
|
|
index.)
|
|
</para>
|
|
|
|
<note>
|
|
<para>
|
|
<structfield>consrc</structfield> is not updated when referenced objects
|
|
change; for example, it won't track renaming of columns. Rather than
|
|
relying on this field, it's best to use <function>pg_get_constraintdef()</>
|
|
to extract the definition of a check constraint.
|
|
</para>
|
|
</note>
|
|
|
|
<note>
|
|
<para>
|
|
<literal>pg_class.relchecks</literal> needs to agree with the
|
|
number of check-constraint entries found in this table for each
|
|
relation. Also, <literal>pg_class.relhasexclusion</literal> must
|
|
be true if there are any exclusion-constraint entries for the relation.
|
|
</para>
|
|
</note>
|
|
|
|
</sect1>
|
|
|
|
<sect1 id="catalog-pg-conversion">
|
|
<title><structname>pg_conversion</structname></title>
|
|
|
|
<indexterm zone="catalog-pg-conversion">
|
|
<primary>pg_conversion</primary>
|
|
</indexterm>
|
|
|
|
<para>
|
|
The catalog <structname>pg_conversion</structname> describes the
|
|
available encoding conversion procedures. See
|
|
<xref linkend="sql-createconversion" endterm="sql-createconversion-title">
|
|
for more information.
|
|
</para>
|
|
|
|
<table>
|
|
<title><structname>pg_conversion</> Columns</title>
|
|
|
|
<tgroup cols="4">
|
|
<thead>
|
|
<row>
|
|
<entry>Name</entry>
|
|
<entry>Type</entry>
|
|
<entry>References</entry>
|
|
<entry>Description</entry>
|
|
</row>
|
|
</thead>
|
|
|
|
<tbody>
|
|
<row>
|
|
<entry><structfield>conname</structfield></entry>
|
|
<entry><type>name</type></entry>
|
|
<entry></entry>
|
|
<entry>Conversion name (unique within a namespace)</entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry><structfield>connamespace</structfield></entry>
|
|
<entry><type>oid</type></entry>
|
|
<entry><literal><link linkend="catalog-pg-namespace"><structname>pg_namespace</structname></link>.oid</literal></entry>
|
|
<entry>
|
|
The OID of the namespace that contains this conversion
|
|
</entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry><structfield>conowner</structfield></entry>
|
|
<entry><type>oid</type></entry>
|
|
<entry><literal><link linkend="catalog-pg-authid"><structname>pg_authid</structname></link>.oid</literal></entry>
|
|
<entry>Owner of the conversion</entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry><structfield>conforencoding</structfield></entry>
|
|
<entry><type>int4</type></entry>
|
|
<entry></entry>
|
|
<entry>Source encoding ID</entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry><structfield>contoencoding</structfield></entry>
|
|
<entry><type>int4</type></entry>
|
|
<entry></entry>
|
|
<entry>Destination encoding ID</entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry><structfield>conproc</structfield></entry>
|
|
<entry><type>regproc</type></entry>
|
|
<entry><literal><link linkend="catalog-pg-proc"><structname>pg_proc</structname></link>.oid</literal></entry>
|
|
<entry>Conversion procedure</entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry><structfield>condefault</structfield></entry>
|
|
<entry><type>bool</type></entry>
|
|
<entry></entry>
|
|
<entry>True if this is the default conversion</entry>
|
|
</row>
|
|
|
|
</tbody>
|
|
</tgroup>
|
|
</table>
|
|
|
|
</sect1>
|
|
|
|
<sect1 id="catalog-pg-database">
|
|
<title><structname>pg_database</structname></title>
|
|
|
|
<indexterm zone="catalog-pg-database">
|
|
<primary>pg_database</primary>
|
|
</indexterm>
|
|
|
|
<para>
|
|
The catalog <structname>pg_database</structname> stores information about
|
|
the available databases. Databases are created with the <xref
|
|
linkend="sql-createdatabase" endterm="sql-createdatabase-title"> command.
|
|
Consult <xref linkend="managing-databases"> for details about the meaning
|
|
of some of the parameters.
|
|
</para>
|
|
|
|
<para>
|
|
Unlike most system catalogs, <structname>pg_database</structname>
|
|
is shared across all databases of a cluster: there is only one
|
|
copy of <structname>pg_database</structname> per cluster, not
|
|
one per database.
|
|
</para>
|
|
|
|
<table>
|
|
<title><structname>pg_database</> Columns</title>
|
|
|
|
<tgroup cols="4">
|
|
<thead>
|
|
<row>
|
|
<entry>Name</entry>
|
|
<entry>Type</entry>
|
|
<entry>References</entry>
|
|
<entry>Description</entry>
|
|
</row>
|
|
</thead>
|
|
|
|
<tbody>
|
|
<row>
|
|
<entry><structfield>datname</structfield></entry>
|
|
<entry><type>name</type></entry>
|
|
<entry></entry>
|
|
<entry>Database name</entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry><structfield>datdba</structfield></entry>
|
|
<entry><type>oid</type></entry>
|
|
<entry><literal><link linkend="catalog-pg-authid"><structname>pg_authid</structname></link>.oid</literal></entry>
|
|
<entry>Owner of the database, usually the user who created it</entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry><structfield>encoding</structfield></entry>
|
|
<entry><type>int4</type></entry>
|
|
<entry></entry>
|
|
<entry>Character encoding for this database
|
|
(<function>pg_encoding_to_char()</function> can translate
|
|
this number to the encoding name)</entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry><structfield>datcollate</structfield></entry>
|
|
<entry><type>name</type></entry>
|
|
<entry></entry>
|
|
<entry>LC_COLLATE for this database</entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry><structfield>datctype</structfield></entry>
|
|
<entry><type>name</type></entry>
|
|
<entry></entry>
|
|
<entry>LC_CTYPE for this database</entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry><structfield>datistemplate</structfield></entry>
|
|
<entry><type>bool</type></entry>
|
|
<entry></entry>
|
|
<entry>
|
|
If true then this database can be used in the
|
|
<literal>TEMPLATE</literal> clause of <command>CREATE
|
|
DATABASE</command> to create a new database as a clone of
|
|
this one
|
|
</entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry><structfield>datallowconn</structfield></entry>
|
|
<entry><type>bool</type></entry>
|
|
<entry></entry>
|
|
<entry>
|
|
If false then no one can connect to this database. This is
|
|
used to protect the <literal>template0</> database from being altered
|
|
</entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry><structfield>datconnlimit</structfield></entry>
|
|
<entry><type>int4</type></entry>
|
|
<entry></entry>
|
|
<entry>
|
|
Sets maximum number of concurrent connections that can be made
|
|
to this database. -1 means no limit
|
|
</entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry><structfield>datlastsysoid</structfield></entry>
|
|
<entry><type>oid</type></entry>
|
|
<entry></entry>
|
|
<entry>
|
|
Last system OID in the database; useful
|
|
particularly to <application>pg_dump</application>
|
|
</entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry><structfield>datfrozenxid</structfield></entry>
|
|
<entry><type>xid</type></entry>
|
|
<entry></entry>
|
|
<entry>
|
|
All transaction IDs before this one have been replaced with a permanent
|
|
(<quote>frozen</>) transaction ID in this database. This is used to
|
|
track whether the database needs to be vacuumed in order to prevent
|
|
transaction ID wraparound or to allow <literal>pg_clog</> to be shrunk.
|
|
It is the minimum of the per-table
|
|
<structname>pg_class</>.<structfield>relfrozenxid</> values
|
|
</entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry><structfield>dattablespace</structfield></entry>
|
|
<entry><type>oid</type></entry>
|
|
<entry><literal><link linkend="catalog-pg-tablespace"><structname>pg_tablespace</structname></link>.oid</literal></entry>
|
|
<entry>
|
|
The default tablespace for the database.
|
|
Within this database, all tables for which
|
|
<structname>pg_class</>.<structfield>reltablespace</> is zero
|
|
will be stored in this tablespace; in particular, all the non-shared
|
|
system catalogs will be there
|
|
</entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry><structfield>datacl</structfield></entry>
|
|
<entry><type>aclitem[]</type></entry>
|
|
<entry></entry>
|
|
<entry>
|
|
Access privileges; see
|
|
<xref linkend="sql-grant" endterm="sql-grant-title"> and
|
|
<xref linkend="sql-revoke" endterm="sql-revoke-title">
|
|
for details
|
|
</entry>
|
|
</row>
|
|
</tbody>
|
|
</tgroup>
|
|
</table>
|
|
</sect1>
|
|
|
|
|
|
<sect1 id="catalog-pg-default-acl">
|
|
<title><structname>pg_default_acl</structname></title>
|
|
|
|
<indexterm zone="catalog-pg-default-acl">
|
|
<primary>pg_default_acl</primary>
|
|
</indexterm>
|
|
|
|
<para>
|
|
The catalog <structname>pg_default_acl</> stores initial
|
|
privileges to be assigned to newly created objects.
|
|
</para>
|
|
|
|
<table>
|
|
<title><structname>pg_default_acl</> Columns</title>
|
|
|
|
<tgroup cols="4">
|
|
<thead>
|
|
<row>
|
|
<entry>Name</entry>
|
|
<entry>Type</entry>
|
|
<entry>References</entry>
|
|
<entry>Description</entry>
|
|
</row>
|
|
</thead>
|
|
|
|
<tbody>
|
|
<row>
|
|
<entry><structfield>defaclrole</structfield></entry>
|
|
<entry><type>oid</type></entry>
|
|
<entry><literal><link linkend="catalog-pg-authid"><structname>pg_authid</structname></link>.oid</literal></entry>
|
|
<entry>The OID of the role associated with this entry</entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry><structfield>defaclnamespace</structfield></entry>
|
|
<entry><type>oid</type></entry>
|
|
<entry><literal><link linkend="catalog-pg-namespace"><structname>pg_namespace</structname></link>.oid</literal></entry>
|
|
<entry>The OID of the namespace associated with this entry,
|
|
or 0 if none</entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry><structfield>defaclobjtype</structfield></entry>
|
|
<entry><type>char</type></entry>
|
|
<entry></entry>
|
|
<entry>
|
|
Type of object this entry is for:
|
|
<literal>r</> = relation (table, view),
|
|
<literal>S</> = sequence,
|
|
<literal>f</> = function
|
|
</entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry><structfield>defaclacl</structfield></entry>
|
|
<entry><type>aclitem[]</type></entry>
|
|
<entry></entry>
|
|
<entry>
|
|
Access privileges that this type of object should have on creation
|
|
</entry>
|
|
</row>
|
|
</tbody>
|
|
</tgroup>
|
|
</table>
|
|
|
|
<para>
|
|
A <structname>pg_default_acl</> entry shows the initial privileges to
|
|
be assigned to an object belonging to the indicated user. There are
|
|
currently two types of entry: <quote>global</> entries with
|
|
<structfield>defaclnamespace</> = 0, and <quote>per-schema</> entries
|
|
that reference a particular schema. If a global entry is present then
|
|
it <emphasis>overrides</> the normal hard-wired default privileges
|
|
for the object type. A per-schema entry, if present, represents privileges
|
|
to be <emphasis>added to</> the global or hard-wired default privileges.
|
|
</para>
|
|
|
|
<para>
|
|
Note that when an ACL entry in another catalog is NULL, it is taken
|
|
to represent the hard-wired default privileges for its object,
|
|
<emphasis>not</> whatever might be in <structname>pg_default_acl</>
|
|
at the moment. <structname>pg_default_acl</> is only consulted during
|
|
object creation.
|
|
</para>
|
|
|
|
</sect1>
|
|
|
|
|
|
<sect1 id="catalog-pg-depend">
|
|
<title><structname>pg_depend</structname></title>
|
|
|
|
<indexterm zone="catalog-pg-depend">
|
|
<primary>pg_depend</primary>
|
|
</indexterm>
|
|
|
|
<para>
|
|
The catalog <structname>pg_depend</structname> records the dependency
|
|
relationships between database objects. This information allows
|
|
<command>DROP</> commands to find which other objects must be dropped
|
|
by <command>DROP CASCADE</> or prevent dropping in the <command>DROP
|
|
RESTRICT</> case.
|
|
</para>
|
|
|
|
<para>
|
|
See also <link linkend="catalog-pg-shdepend"><structname>pg_shdepend</structname></link>,
|
|
which performs a similar function for dependencies involving objects
|
|
that are shared across a database cluster.
|
|
</para>
|
|
|
|
<table>
|
|
<title><structname>pg_depend</> Columns</title>
|
|
|
|
<tgroup cols="4">
|
|
<thead>
|
|
<row>
|
|
<entry>Name</entry>
|
|
<entry>Type</entry>
|
|
<entry>References</entry>
|
|
<entry>Description</entry>
|
|
</row>
|
|
</thead>
|
|
|
|
<tbody>
|
|
<row>
|
|
<entry><structfield>classid</structfield></entry>
|
|
<entry><type>oid</type></entry>
|
|
<entry><literal><link linkend="catalog-pg-class"><structname>pg_class</structname></link>.oid</literal></entry>
|
|
<entry>The OID of the system catalog the dependent object is in</entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry><structfield>objid</structfield></entry>
|
|
<entry><type>oid</type></entry>
|
|
<entry>any OID column</entry>
|
|
<entry>The OID of the specific dependent object</entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry><structfield>objsubid</structfield></entry>
|
|
<entry><type>int4</type></entry>
|
|
<entry></entry>
|
|
<entry>
|
|
For a table column, this is the column number (the
|
|
<structfield>objid</> and <structfield>classid</> refer to the
|
|
table itself). For all other object types, this column is
|
|
zero
|
|
</entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry><structfield>refclassid</structfield></entry>
|
|
<entry><type>oid</type></entry>
|
|
<entry><literal><link linkend="catalog-pg-class"><structname>pg_class</structname></link>.oid</literal></entry>
|
|
<entry>The OID of the system catalog the referenced object is in</entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry><structfield>refobjid</structfield></entry>
|
|
<entry><type>oid</type></entry>
|
|
<entry>any OID column</entry>
|
|
<entry>The OID of the specific referenced object</entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry><structfield>refobjsubid</structfield></entry>
|
|
<entry><type>int4</type></entry>
|
|
<entry></entry>
|
|
<entry>
|
|
For a table column, this is the column number (the
|
|
<structfield>refobjid</> and <structfield>refclassid</> refer
|
|
to the table itself). For all other object types, this column
|
|
is zero
|
|
</entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry><structfield>deptype</structfield></entry>
|
|
<entry><type>char</type></entry>
|
|
<entry></entry>
|
|
<entry>
|
|
A code defining the specific semantics of this dependency relationship; see text
|
|
</entry>
|
|
</row>
|
|
|
|
</tbody>
|
|
</tgroup>
|
|
</table>
|
|
|
|
<para>
|
|
In all cases, a <structname>pg_depend</structname> entry indicates that the
|
|
referenced object cannot be dropped without also dropping the dependent
|
|
object. However, there are several subflavors identified by
|
|
<structfield>deptype</>:
|
|
|
|
<variablelist>
|
|
<varlistentry>
|
|
<term><symbol>DEPENDENCY_NORMAL</> (<literal>n</>)</term>
|
|
<listitem>
|
|
<para>
|
|
A normal relationship between separately-created objects. The
|
|
dependent object can be dropped without affecting the
|
|
referenced object. The referenced object can only be dropped
|
|
by specifying <literal>CASCADE</>, in which case the dependent
|
|
object is dropped, too. Example: a table column has a normal
|
|
dependency on its data type.
|
|
</para>
|
|
</listitem>
|
|
</varlistentry>
|
|
|
|
<varlistentry>
|
|
<term><symbol>DEPENDENCY_AUTO</> (<literal>a</>)</term>
|
|
<listitem>
|
|
<para>
|
|
The dependent object can be dropped separately from the
|
|
referenced object, and should be automatically dropped
|
|
(regardless of <literal>RESTRICT</> or <literal>CASCADE</>
|
|
mode) if the referenced object is dropped. Example: a named
|
|
constraint on a table is made autodependent on the table, so
|
|
that it will go away if the table is dropped.
|
|
</para>
|
|
</listitem>
|
|
</varlistentry>
|
|
|
|
<varlistentry>
|
|
<term><symbol>DEPENDENCY_INTERNAL</> (<literal>i</>)</term>
|
|
<listitem>
|
|
<para>
|
|
The dependent object was created as part of creation of the
|
|
referenced object, and is really just a part of its internal
|
|
implementation. A <command>DROP</> of the dependent object
|
|
will be disallowed outright (we'll tell the user to issue a
|
|
<command>DROP</> against the referenced object, instead). A
|
|
<command>DROP</> of the referenced object will be propagated
|
|
through to drop the dependent object whether
|
|
<command>CASCADE</> is specified or not. Example: a trigger
|
|
that's created to enforce a foreign-key constraint is made
|
|
internally dependent on the constraint's
|
|
<structname>pg_constraint</> entry.
|
|
</para>
|
|
</listitem>
|
|
</varlistentry>
|
|
|
|
<varlistentry>
|
|
<term><symbol>DEPENDENCY_PIN</> (<literal>p</>)</term>
|
|
<listitem>
|
|
<para>
|
|
There is no dependent object; this type of entry is a signal
|
|
that the system itself depends on the referenced object, and so
|
|
that object must never be deleted. Entries of this type are
|
|
created only by <command>initdb</command>. The columns for the
|
|
dependent object contain zeroes.
|
|
</para>
|
|
</listitem>
|
|
</varlistentry>
|
|
</variablelist>
|
|
|
|
Other dependency flavors might be needed in future.
|
|
</para>
|
|
|
|
</sect1>
|
|
|
|
|
|
<sect1 id="catalog-pg-description">
|
|
<title><structname>pg_description</structname></title>
|
|
|
|
<indexterm zone="catalog-pg-description">
|
|
<primary>pg_description</primary>
|
|
</indexterm>
|
|
|
|
<para>
|
|
The catalog <structname>pg_description</> stores optional descriptions
|
|
(comments) for each database object. Descriptions can be manipulated
|
|
with the <xref linkend="sql-comment" endterm="sql-comment-title"> command and viewed with
|
|
<application>psql</application>'s <literal>\d</literal> commands.
|
|
Descriptions of many built-in system objects are provided in the initial
|
|
contents of <structname>pg_description</structname>.
|
|
</para>
|
|
|
|
<para>
|
|
See also <link linkend="catalog-pg-shdescription"><structname>pg_shdescription</structname></link>,
|
|
which performs a similar function for descriptions involving objects that
|
|
are shared across a database cluster.
|
|
</para>
|
|
|
|
<table>
|
|
<title><structname>pg_description</> Columns</title>
|
|
|
|
<tgroup cols="4">
|
|
<thead>
|
|
<row>
|
|
<entry>Name</entry>
|
|
<entry>Type</entry>
|
|
<entry>References</entry>
|
|
<entry>Description</entry>
|
|
</row>
|
|
</thead>
|
|
|
|
<tbody>
|
|
<row>
|
|
<entry><structfield>objoid</structfield></entry>
|
|
<entry><type>oid</type></entry>
|
|
<entry>any OID column</entry>
|
|
<entry>The OID of the object this description pertains to</entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry><structfield>classoid</structfield></entry>
|
|
<entry><type>oid</type></entry>
|
|
<entry><literal><link linkend="catalog-pg-class"><structname>pg_class</structname></link>.oid</literal></entry>
|
|
<entry>The OID of the system catalog this object appears in</entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry><structfield>objsubid</structfield></entry>
|
|
<entry><type>int4</type></entry>
|
|
<entry></entry>
|
|
<entry>
|
|
For a comment on a table column, this is the column number (the
|
|
<structfield>objoid</> and <structfield>classoid</> refer to
|
|
the table itself). For all other object types, this column is
|
|
zero
|
|
</entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry><structfield>description</structfield></entry>
|
|
<entry><type>text</type></entry>
|
|
<entry></entry>
|
|
<entry>Arbitrary text that serves as the description of this object</entry>
|
|
</row>
|
|
</tbody>
|
|
</tgroup>
|
|
</table>
|
|
|
|
</sect1>
|
|
|
|
|
|
<sect1 id="catalog-pg-enum">
|
|
<title><structname>pg_enum</structname></title>
|
|
|
|
<indexterm zone="catalog-pg-enum">
|
|
<primary>pg_enum</primary>
|
|
</indexterm>
|
|
|
|
<para>
|
|
The <structname>pg_enum</structname> catalog contains entries
|
|
matching enum types to their associated values and labels. The
|
|
internal representation of a given enum value is actually the OID
|
|
of its associated row in <structname>pg_enum</structname>. The
|
|
OIDs for a particular enum type are guaranteed to be ordered in
|
|
the way the type should sort, but there is no guarantee about the
|
|
ordering of OIDs of unrelated enum types.
|
|
</para>
|
|
|
|
<table>
|
|
<title><structname>pg_enum</> Columns</title>
|
|
|
|
<tgroup cols="4">
|
|
<thead>
|
|
<row>
|
|
<entry>Name</entry>
|
|
<entry>Type</entry>
|
|
<entry>References</entry>
|
|
<entry>Description</entry>
|
|
</row>
|
|
</thead>
|
|
|
|
<tbody>
|
|
<row>
|
|
<entry><structfield>enumtypid</structfield></entry>
|
|
<entry><type>oid</type></entry>
|
|
<entry><literal><link linkend="catalog-pg-type"><structname>pg_type</structname></link>.oid</literal></entry>
|
|
<entry>The OID of the <structname>pg_type</> entry owning this enum value</entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry><structfield>enumlabel</structfield></entry>
|
|
<entry><type>name</type></entry>
|
|
<entry></entry>
|
|
<entry>The textual label for this enum value</entry>
|
|
</row>
|
|
</tbody>
|
|
</tgroup>
|
|
</table>
|
|
</sect1>
|
|
|
|
|
|
<sect1 id="catalog-pg-foreign-data-wrapper">
|
|
<title><structname>pg_foreign_data_wrapper</structname></title>
|
|
|
|
<indexterm zone="catalog-pg-foreign-data-wrapper">
|
|
<primary>pg_foreign_data_wrapper</primary>
|
|
</indexterm>
|
|
|
|
<para>
|
|
The catalog <structname>pg_foreign_data_wrapper</structname> stores
|
|
foreign-data wrapper definitions. A foreign-data wrapper is the
|
|
mechanism by which external data, residing on foreign servers, is
|
|
accessed.
|
|
</para>
|
|
|
|
<table>
|
|
<title><structname>pg_foreign_data_wrapper</> Columns</title>
|
|
|
|
<tgroup cols="4">
|
|
<thead>
|
|
<row>
|
|
<entry>Name</entry>
|
|
<entry>Type</entry>
|
|
<entry>References</entry>
|
|
<entry>Description</entry>
|
|
</row>
|
|
</thead>
|
|
|
|
<tbody>
|
|
<row>
|
|
<entry><structfield>fdwname</structfield></entry>
|
|
<entry><type>name</type></entry>
|
|
<entry></entry>
|
|
<entry>Name of the foreign-data wrapper</entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry><structfield>fdwowner</structfield></entry>
|
|
<entry><type>oid</type></entry>
|
|
<entry><literal><link linkend="catalog-pg-authid"><structname>pg_authid</structname></link>.oid</literal></entry>
|
|
<entry>Owner of the foreign-data wrapper</entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry><structfield>fdwvalidator</structfield></entry>
|
|
<entry><type>oid</type></entry>
|
|
<entry><literal><link linkend="catalog-pg-proc"><structname>pg_proc</structname></link>.oid</literal></entry>
|
|
<entry>
|
|
References a validator function that is responsible for
|
|
checking the validity of the generic options given to the
|
|
foreign-data wrapper, as well as to foreign servers and user
|
|
mappings using the foreign-data wrapper. Zero if no validator
|
|
is provided.
|
|
</entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry><structfield>fdwacl</structfield></entry>
|
|
<entry><type>aclitem[]</type></entry>
|
|
<entry></entry>
|
|
<entry>
|
|
Access privileges; see
|
|
<xref linkend="sql-grant" endterm="sql-grant-title"> and
|
|
<xref linkend="sql-revoke" endterm="sql-revoke-title">
|
|
for details
|
|
</entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry><structfield>fdwoptions</structfield></entry>
|
|
<entry><type>text[]</type></entry>
|
|
<entry></entry>
|
|
<entry>
|
|
Foreign-data wrapper specific options, as <quote>keyword=value</> strings
|
|
</entry>
|
|
</row>
|
|
</tbody>
|
|
</tgroup>
|
|
</table>
|
|
</sect1>
|
|
|
|
|
|
<sect1 id="catalog-pg-foreign-server">
|
|
<title><structname>pg_foreign_server</structname></title>
|
|
|
|
<indexterm zone="catalog-pg-foreign-server">
|
|
<primary>pg_foreign_server</primary>
|
|
</indexterm>
|
|
|
|
<para>
|
|
The catalog <structname>pg_foreign_server</structname> stores
|
|
foreign server definitions. A foreign server describes the
|
|
connection to a remote server, managing external data. Foreign
|
|
servers are accessed via foreign-data wrappers.
|
|
</para>
|
|
|
|
<table>
|
|
<title><structname>pg_foreign_server</> Columns</title>
|
|
|
|
<tgroup cols="4">
|
|
<thead>
|
|
<row>
|
|
<entry>Name</entry>
|
|
<entry>Type</entry>
|
|
<entry>References</entry>
|
|
<entry>Description</entry>
|
|
</row>
|
|
</thead>
|
|
|
|
<tbody>
|
|
<row>
|
|
<entry><structfield>srvname</structfield></entry>
|
|
<entry><type>name</type></entry>
|
|
<entry></entry>
|
|
<entry>Name of the foreign server</entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry><structfield>srvowner</structfield></entry>
|
|
<entry><type>oid</type></entry>
|
|
<entry><literal><link linkend="catalog-pg-authid"><structname>pg_authid</structname></link>.oid</literal></entry>
|
|
<entry>Owner of the foreign server</entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry><structfield>srvfdw</structfield></entry>
|
|
<entry><type>oid</type></entry>
|
|
<entry><literal><link linkend="catalog-pg-foreign-data-wrapper"><structname>pg_foreign_data_wrapper</structname></link>.oid</literal></entry>
|
|
<entry>The OID of the foreign-data wrapper of this foreign server</entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry><structfield>srvtype</structfield></entry>
|
|
<entry><type>text</type></entry>
|
|
<entry></entry>
|
|
<entry>Type of the server (optional)</entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry><structfield>srvversion</structfield></entry>
|
|
<entry><type>text</type></entry>
|
|
<entry></entry>
|
|
<entry>Version of the server (optional)</entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry><structfield>srvacl</structfield></entry>
|
|
<entry><type>aclitem[]</type></entry>
|
|
<entry></entry>
|
|
<entry>
|
|
Access privileges; see
|
|
<xref linkend="sql-grant" endterm="sql-grant-title"> and
|
|
<xref linkend="sql-revoke" endterm="sql-revoke-title">
|
|
for details
|
|
</entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry><structfield>srvoptions</structfield></entry>
|
|
<entry><type>text[]</type></entry>
|
|
<entry></entry>
|
|
<entry>
|
|
Foreign server specific options, as <quote>keyword=value</> strings.
|
|
</entry>
|
|
</row>
|
|
</tbody>
|
|
</tgroup>
|
|
</table>
|
|
</sect1>
|
|
|
|
|
|
<sect1 id="catalog-pg-index">
|
|
<title><structname>pg_index</structname></title>
|
|
|
|
<indexterm zone="catalog-pg-index">
|
|
<primary>pg_index</primary>
|
|
</indexterm>
|
|
|
|
<para>
|
|
The catalog <structname>pg_index</structname> contains part of the information
|
|
about indexes. The rest is mostly in
|
|
<structname>pg_class</structname>.
|
|
</para>
|
|
|
|
<table>
|
|
<title><structname>pg_index</> Columns</title>
|
|
|
|
<tgroup cols="4">
|
|
<thead>
|
|
<row>
|
|
<entry>Name</entry>
|
|
<entry>Type</entry>
|
|
<entry>References</entry>
|
|
<entry>Description</entry>
|
|
</row>
|
|
</thead>
|
|
|
|
<tbody>
|
|
<row>
|
|
<entry><structfield>indexrelid</structfield></entry>
|
|
<entry><type>oid</type></entry>
|
|
<entry><literal><link linkend="catalog-pg-class"><structname>pg_class</structname></link>.oid</literal></entry>
|
|
<entry>The OID of the <structname>pg_class</> entry for this index</entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry><structfield>indrelid</structfield></entry>
|
|
<entry><type>oid</type></entry>
|
|
<entry><literal><link linkend="catalog-pg-class"><structname>pg_class</structname></link>.oid</literal></entry>
|
|
<entry>The OID of the <structname>pg_class</> entry for the table this index is for</entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry><structfield>indnatts</structfield></entry>
|
|
<entry><type>int2</type></entry>
|
|
<entry></entry>
|
|
<entry>The number of columns in the index (duplicates
|
|
<literal>pg_class.relnatts</literal>)</entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry><structfield>indisunique</structfield></entry>
|
|
<entry><type>bool</type></entry>
|
|
<entry></entry>
|
|
<entry>If true, this is a unique index</entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry><structfield>indisprimary</structfield></entry>
|
|
<entry><type>bool</type></entry>
|
|
<entry></entry>
|
|
<entry>If true, this index represents the primary key of the table
|
|
(<structfield>indisunique</> should always be true when this is true)</entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry><structfield>indimmediate</structfield></entry>
|
|
<entry><type>bool</type></entry>
|
|
<entry></entry>
|
|
<entry>If true, the uniqueness check is enforced immediately on insertion
|
|
(<structfield>indisunique</> should always be true when this is true)</entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry><structfield>indisclustered</structfield></entry>
|
|
<entry><type>bool</type></entry>
|
|
<entry></entry>
|
|
<entry>If true, the table was last clustered on this index</entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry><structfield>indisvalid</structfield></entry>
|
|
<entry><type>bool</type></entry>
|
|
<entry></entry>
|
|
<entry>
|
|
If true, the index is currently valid for queries. False means the
|
|
index is possibly incomplete: it must still be modified by
|
|
<command>INSERT</>/<command>UPDATE</> operations, but it cannot safely
|
|
be used for queries. If it is unique, the uniqueness property is not
|
|
true either
|
|
</entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry><structfield>indcheckxmin</structfield></entry>
|
|
<entry><type>bool</type></entry>
|
|
<entry></entry>
|
|
<entry>
|
|
If true, queries must not use the index until the <structfield>xmin</>
|
|
of this <structname>pg_index</> row is below their TransactionXmin
|
|
event horizon, because the table may contain broken HOT chains with
|
|
incompatible rows that they can see
|
|
</entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry><structfield>indisready</structfield></entry>
|
|
<entry><type>bool</type></entry>
|
|
<entry></entry>
|
|
<entry>
|
|
If true, the index is currently ready for inserts. False means the
|
|
index must be ignored by <command>INSERT</>/<command>UPDATE</>
|
|
operations
|
|
</entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry><structfield>indkey</structfield></entry>
|
|
<entry><type>int2vector</type></entry>
|
|
<entry><literal><link linkend="catalog-pg-attribute"><structname>pg_attribute</structname></link>.attnum</literal></entry>
|
|
<entry>
|
|
This is an array of <structfield>indnatts</structfield> values that
|
|
indicate which table columns this index indexes. For example a value
|
|
of <literal>1 3</literal> would mean that the first and the third table
|
|
columns make up the index key. A zero in this array indicates that the
|
|
corresponding index attribute is an expression over the table columns,
|
|
rather than a simple column reference
|
|
</entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry><structfield>indclass</structfield></entry>
|
|
<entry><type>oidvector</type></entry>
|
|
<entry><literal><link linkend="catalog-pg-opclass"><structname>pg_opclass</structname></link>.oid</literal></entry>
|
|
<entry>
|
|
For each column in the index key, this contains the OID of
|
|
the operator class to use. See
|
|
<link linkend="catalog-pg-opclass"><structname>pg_opclass</structname></link> for details
|
|
</entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry><structfield>indoption</structfield></entry>
|
|
<entry><type>int2vector</type></entry>
|
|
<entry></entry>
|
|
<entry>
|
|
This is an array of <structfield>indnatts</structfield> values that
|
|
store per-column flag bits. The meaning of the bits is defined by
|
|
the index's access method
|
|
</entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry><structfield>indexprs</structfield></entry>
|
|
<entry><type>text</type></entry>
|
|
<entry></entry>
|
|
<entry>Expression trees (in <function>nodeToString()</function> representation)
|
|
for index attributes that are not simple column references. This is a
|
|
list with one element for each zero entry in <structfield>indkey</>.
|
|
NULL if all index attributes are simple references</entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry><structfield>indpred</structfield></entry>
|
|
<entry><type>text</type></entry>
|
|
<entry></entry>
|
|
<entry>Expression tree (in <function>nodeToString()</function> representation)
|
|
for partial index predicate. NULL if not a partial index</entry>
|
|
</row>
|
|
</tbody>
|
|
</tgroup>
|
|
</table>
|
|
|
|
</sect1>
|
|
|
|
|
|
<sect1 id="catalog-pg-inherits">
|
|
<title><structname>pg_inherits</structname></title>
|
|
|
|
<indexterm zone="catalog-pg-inherits">
|
|
<primary>pg_inherits</primary>
|
|
</indexterm>
|
|
|
|
<para>
|
|
The catalog <structname>pg_inherits</> records information about
|
|
table inheritance hierarchies. There is one entry for each direct
|
|
child table in the database. (Indirect inheritance can be determined
|
|
by following chains of entries.)
|
|
</para>
|
|
|
|
<table>
|
|
<title><structname>pg_inherits</> Columns</title>
|
|
|
|
<tgroup cols="4">
|
|
<thead>
|
|
<row>
|
|
<entry>Name</entry>
|
|
<entry>Type</entry>
|
|
<entry>References</entry>
|
|
<entry>Description</entry>
|
|
</row>
|
|
</thead>
|
|
|
|
<tbody>
|
|
<row>
|
|
<entry><structfield>inhrelid</structfield></entry>
|
|
<entry><type>oid</type></entry>
|
|
<entry><literal><link linkend="catalog-pg-class"><structname>pg_class</structname></link>.oid</literal></entry>
|
|
<entry>
|
|
The OID of the child table
|
|
</entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry><structfield>inhparent</structfield></entry>
|
|
<entry><type>oid</type></entry>
|
|
<entry><literal><link linkend="catalog-pg-class"><structname>pg_class</structname></link>.oid</literal></entry>
|
|
<entry>
|
|
The OID of the parent table
|
|
</entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry><structfield>inhseqno</structfield></entry>
|
|
<entry><type>int4</type></entry>
|
|
<entry></entry>
|
|
<entry>
|
|
If there is more than one direct parent for a child table (multiple
|
|
inheritance), this number tells the order in which the
|
|
inherited columns are to be arranged. The count starts at 1
|
|
</entry>
|
|
</row>
|
|
</tbody>
|
|
</tgroup>
|
|
</table>
|
|
|
|
</sect1>
|
|
|
|
|
|
<sect1 id="catalog-pg-language">
|
|
<title><structname>pg_language</structname></title>
|
|
|
|
<indexterm zone="catalog-pg-language">
|
|
<primary>pg_language</primary>
|
|
</indexterm>
|
|
|
|
<para>
|
|
The catalog <structname>pg_language</structname> registers
|
|
languages in which you can write functions or stored procedures.
|
|
See <xref linkend="sql-createlanguage" endterm="sql-createlanguage-title">
|
|
and <xref linkend="xplang"> for more information about language handlers.
|
|
</para>
|
|
|
|
<table>
|
|
<title><structname>pg_language</> Columns</title>
|
|
|
|
<tgroup cols="4">
|
|
<thead>
|
|
<row>
|
|
<entry>Name</entry>
|
|
<entry>Type</entry>
|
|
<entry>References</entry>
|
|
<entry>Description</entry>
|
|
</row>
|
|
</thead>
|
|
|
|
<tbody>
|
|
<row>
|
|
<entry><structfield>lanname</structfield></entry>
|
|
<entry><type>name</type></entry>
|
|
<entry></entry>
|
|
<entry>Name of the language</entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry><structfield>lanowner</structfield></entry>
|
|
<entry><type>oid</type></entry>
|
|
<entry><literal><link linkend="catalog-pg-authid"><structname>pg_authid</structname></link>.oid</literal></entry>
|
|
<entry>Owner of the language</entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry><structfield>lanispl</structfield></entry>
|
|
<entry><type>bool</type></entry>
|
|
<entry></entry>
|
|
<entry>
|
|
This is false for internal languages (such as
|
|
<acronym>SQL</acronym>) and true for user-defined languages.
|
|
Currently, <application>pg_dump</application> still uses this
|
|
to determine which languages need to be dumped, but this might be
|
|
replaced by a different mechanism in the future
|
|
</entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry><structfield>lanpltrusted</structfield></entry>
|
|
<entry><type>bool</type></entry>
|
|
<entry></entry>
|
|
<entry>
|
|
True if this is a trusted language, which means that it is believed
|
|
not to grant access to anything outside the normal SQL execution
|
|
environment. Only superusers can create functions in untrusted
|
|
languages
|
|
</entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry><structfield>lanplcallfoid</structfield></entry>
|
|
<entry><type>oid</type></entry>
|
|
<entry><literal><link linkend="catalog-pg-proc"><structname>pg_proc</structname></link>.oid</literal></entry>
|
|
<entry>
|
|
For noninternal languages this references the language
|
|
handler, which is a special function that is responsible for
|
|
executing all functions that are written in the particular
|
|
language
|
|
</entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry><structfield>laninline</structfield></entry>
|
|
<entry><type>oid</type></entry>
|
|
<entry><literal><link linkend="catalog-pg-proc"><structname>pg_proc</structname></link>.oid</literal></entry>
|
|
<entry>
|
|
This references a function that is responsible for executing
|
|
<quote>inline</> anonymous code blocks
|
|
(<xref linkend="sql-do" endterm="sql-do-title"> blocks).
|
|
Zero if inline blocks are not supported
|
|
</entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry><structfield>lanvalidator</structfield></entry>
|
|
<entry><type>oid</type></entry>
|
|
<entry><literal><link linkend="catalog-pg-proc"><structname>pg_proc</structname></link>.oid</literal></entry>
|
|
<entry>
|
|
This references a language validator function that is responsible
|
|
for checking the syntax and validity of new functions when they
|
|
are created. Zero if no validator is provided
|
|
</entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry><structfield>lanacl</structfield></entry>
|
|
<entry><type>aclitem[]</type></entry>
|
|
<entry></entry>
|
|
<entry>
|
|
Access privileges; see
|
|
<xref linkend="sql-grant" endterm="sql-grant-title"> and
|
|
<xref linkend="sql-revoke" endterm="sql-revoke-title">
|
|
for details
|
|
</entry>
|
|
</row>
|
|
</tbody>
|
|
</tgroup>
|
|
</table>
|
|
|
|
</sect1>
|
|
|
|
|
|
<sect1 id="catalog-pg-largeobject">
|
|
<title><structname>pg_largeobject</structname></title>
|
|
|
|
<indexterm zone="catalog-pg-largeobject">
|
|
<primary>pg_largeobject</primary>
|
|
</indexterm>
|
|
|
|
<para>
|
|
The catalog <structname>pg_largeobject</structname> holds the data making up
|
|
<quote>large objects</quote>. A large object is identified by an OID
|
|
assigned when it is created. Each large object is broken into
|
|
segments or <quote>pages</> small enough to be conveniently stored as rows
|
|
in <structname>pg_largeobject</structname>.
|
|
The amount of data per page is defined to be <symbol>LOBLKSIZE</> (which is currently
|
|
<literal>BLCKSZ/4</>, or typically 2 kB).
|
|
</para>
|
|
|
|
<para>
|
|
Prior to <productname>PostgreSQL</> 8.5, there was no permission structure
|
|
associated with large objects. As a result,
|
|
<structname>pg_largeobject</structname> was publicly readable and could be
|
|
used to obtain the OIDs (and contents) of all large objects in the system.
|
|
This is no longer the case; use
|
|
<link linkend="catalog-pg-largeobject-metadata">pg_largeobject_metadata</link>
|
|
to obtain a list of large object OIDs.
|
|
</para>
|
|
|
|
<table>
|
|
<title><structname>pg_largeobject</> Columns</title>
|
|
|
|
<tgroup cols="4">
|
|
<thead>
|
|
<row>
|
|
<entry>Name</entry>
|
|
<entry>Type</entry>
|
|
<entry>References</entry>
|
|
<entry>Description</entry>
|
|
</row>
|
|
</thead>
|
|
|
|
<tbody>
|
|
<row>
|
|
<entry><structfield>loid</structfield></entry>
|
|
<entry><type>oid</type></entry>
|
|
<entry><literal><link linkend="catalog-pg-largeobject-metadata"><structname>pg_largeobject_metadata</structname></link>.oid</literal></entry>
|
|
<entry>Identifier of the large object that includes this page</entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry><structfield>pageno</structfield></entry>
|
|
<entry><type>int4</type></entry>
|
|
<entry></entry>
|
|
<entry>Page number of this page within its large object
|
|
(counting from zero)</entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry><structfield>data</structfield></entry>
|
|
<entry><type>bytea</type></entry>
|
|
<entry></entry>
|
|
<entry>
|
|
Actual data stored in the large object.
|
|
This will never be more than <symbol>LOBLKSIZE</> bytes and might be less
|
|
</entry>
|
|
</row>
|
|
</tbody>
|
|
</tgroup>
|
|
</table>
|
|
|
|
<para>
|
|
Each row of <structname>pg_largeobject</structname> holds data
|
|
for one page of a large object, beginning at
|
|
byte offset (<literal>pageno * LOBLKSIZE</>) within the object. The implementation
|
|
allows sparse storage: pages might be missing, and might be shorter than
|
|
<literal>LOBLKSIZE</> bytes even if they are not the last page of the object.
|
|
Missing regions within a large object read as zeroes.
|
|
</para>
|
|
|
|
</sect1>
|
|
|
|
<sect1 id="catalog-pg-largeobject-metadata">
|
|
<title><structname>pg_largeobject_metadata</structname></title>
|
|
|
|
<indexterm zone="catalog-pg-largeobject-metadata">
|
|
<primary>pg_largeobject_metadata</primary>
|
|
</indexterm>
|
|
|
|
<para>
|
|
The catalog <structname>pg_largeobject_metadata</structname>
|
|
holds metadata associated with large objects. The actual large object
|
|
data is stored in
|
|
<link linkend="catalog-pg-largeobject">pg_largeobject</link>.
|
|
</para>
|
|
|
|
<table>
|
|
<title><structname>pg_largeobject_metadata</> Columns</title>
|
|
|
|
<tgroup cols="4">
|
|
<thead>
|
|
<row>
|
|
<entry>Name</entry>
|
|
<entry>Type</entry>
|
|
<entry>References</entry>
|
|
<entry>Description</entry>
|
|
</row>
|
|
</thead>
|
|
|
|
<tbody>
|
|
<row>
|
|
<entry><structfield>lomowner</structfield></entry>
|
|
<entry><type>oid</type></entry>
|
|
<entry><literal><link linkend="catalog-pg-authid"><structname>pg_authid</structname></link>.oid</literal></entry>
|
|
<entry>Owner of the largeobject</entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry><structfield>lomacl</structfield></entry>
|
|
<entry><type>aclitem[]</type></entry>
|
|
<entry></entry>
|
|
<entry>
|
|
Access privileges; see
|
|
<xref linkend="sql-grant" endterm="sql-grant-title"> and
|
|
<xref linkend="sql-revoke" endterm="sql-revoke-title">
|
|
for details
|
|
</entry>
|
|
</row>
|
|
|
|
</tbody>
|
|
</tgroup>
|
|
</table>
|
|
</sect1>
|
|
|
|
<sect1 id="catalog-pg-listener">
|
|
<title><structname>pg_listener</structname></title>
|
|
|
|
<indexterm zone="catalog-pg-listener">
|
|
<primary>pg_listener</primary>
|
|
</indexterm>
|
|
|
|
<para>
|
|
The catalog <structname>pg_listener</structname> supports the
|
|
<xref linkend="sql-listen" endterm="sql-listen-title"> and
|
|
<xref linkend="sql-notify" endterm="sql-notify-title">
|
|
commands. A listener creates an entry in
|
|
<structname>pg_listener</structname> for each notification name
|
|
it is listening for. A notifier scans <structname>pg_listener</structname>
|
|
and updates each matching entry to show that a notification has occurred.
|
|
The notifier also sends a signal (using the PID recorded in the table)
|
|
to awaken the listener from sleep.
|
|
</para>
|
|
|
|
<table>
|
|
<title><structname>pg_listener</> Columns</title>
|
|
|
|
<tgroup cols="3">
|
|
<thead>
|
|
<row>
|
|
<entry>Name</entry>
|
|
<entry>Type</entry>
|
|
<entry>Description</entry>
|
|
</row>
|
|
</thead>
|
|
|
|
<tbody>
|
|
<row>
|
|
<entry><structfield>relname</structfield></entry>
|
|
<entry><type>name</type></entry>
|
|
<entry>
|
|
Notify condition name. (The name need not match any actual
|
|
relation in the database; the name <structfield>relname</> is historical.)
|
|
</entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry><structfield>listenerpid</structfield></entry>
|
|
<entry><type>int4</type></entry>
|
|
<entry>PID of the server process that created this entry</entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry><structfield>notification</structfield></entry>
|
|
<entry><type>int4</type></entry>
|
|
<entry>
|
|
Zero if no event is pending for this listener. If an event is
|
|
pending, the PID of the server process that sent the notification
|
|
</entry>
|
|
</row>
|
|
</tbody>
|
|
</tgroup>
|
|
</table>
|
|
|
|
</sect1>
|
|
|
|
|
|
<sect1 id="catalog-pg-namespace">
|
|
<title><structname>pg_namespace</structname></title>
|
|
|
|
<indexterm zone="catalog-pg-namespace">
|
|
<primary>pg_namespace</primary>
|
|
</indexterm>
|
|
|
|
<para>
|
|
The catalog <structname>pg_namespace</> stores namespaces.
|
|
A namespace is the structure underlying SQL schemas: each namespace
|
|
can have a separate collection of relations, types, etc. without name
|
|
conflicts.
|
|
</para>
|
|
|
|
<table>
|
|
<title><structname>pg_namespace</> Columns</title>
|
|
|
|
<tgroup cols="4">
|
|
<thead>
|
|
<row>
|
|
<entry>Name</entry>
|
|
<entry>Type</entry>
|
|
<entry>References</entry>
|
|
<entry>Description</entry>
|
|
</row>
|
|
</thead>
|
|
|
|
<tbody>
|
|
<row>
|
|
<entry><structfield>nspname</structfield></entry>
|
|
<entry><type>name</type></entry>
|
|
<entry></entry>
|
|
<entry>Name of the namespace</entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry><structfield>nspowner</structfield></entry>
|
|
<entry><type>oid</type></entry>
|
|
<entry><literal><link linkend="catalog-pg-authid"><structname>pg_authid</structname></link>.oid</literal></entry>
|
|
<entry>Owner of the namespace</entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry><structfield>nspacl</structfield></entry>
|
|
<entry><type>aclitem[]</type></entry>
|
|
<entry></entry>
|
|
<entry>
|
|
Access privileges; see
|
|
<xref linkend="sql-grant" endterm="sql-grant-title"> and
|
|
<xref linkend="sql-revoke" endterm="sql-revoke-title">
|
|
for details
|
|
</entry>
|
|
</row>
|
|
</tbody>
|
|
</tgroup>
|
|
</table>
|
|
|
|
</sect1>
|
|
|
|
|
|
<sect1 id="catalog-pg-opclass">
|
|
<title><structname>pg_opclass</structname></title>
|
|
|
|
<indexterm zone="catalog-pg-opclass">
|
|
<primary>pg_opclass</primary>
|
|
</indexterm>
|
|
|
|
<para>
|
|
The catalog <structname>pg_opclass</structname> defines
|
|
index access method operator classes. Each operator class defines
|
|
semantics for index columns of a particular data type and a particular
|
|
index access method. An operator class essentially specifies that a
|
|
particular operator family is applicable to a particular indexable column
|
|
data type. The set of operators from the family that are actually usable
|
|
with the indexed column are whichever ones accept the column's data type
|
|
as their lefthand input.
|
|
</para>
|
|
|
|
<para>
|
|
Operator classes are described at length in <xref linkend="xindex">.
|
|
</para>
|
|
|
|
<table>
|
|
<title><structname>pg_opclass</> Columns</title>
|
|
|
|
<tgroup cols="4">
|
|
<thead>
|
|
<row>
|
|
<entry>Name</entry>
|
|
<entry>Type</entry>
|
|
<entry>References</entry>
|
|
<entry>Description</entry>
|
|
</row>
|
|
</thead>
|
|
<tbody>
|
|
|
|
<row>
|
|
<entry><structfield>opcmethod</structfield></entry>
|
|
<entry><type>oid</type></entry>
|
|
<entry><literal><link linkend="catalog-pg-am"><structname>pg_am</structname></link>.oid</literal></entry>
|
|
<entry>Index access method operator class is for</entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry><structfield>opcname</structfield></entry>
|
|
<entry><type>name</type></entry>
|
|
<entry></entry>
|
|
<entry>Name of this operator class</entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry><structfield>opcnamespace</structfield></entry>
|
|
<entry><type>oid</type></entry>
|
|
<entry><literal><link linkend="catalog-pg-namespace"><structname>pg_namespace</structname></link>.oid</literal></entry>
|
|
<entry>Namespace of this operator class</entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry><structfield>opcowner</structfield></entry>
|
|
<entry><type>oid</type></entry>
|
|
<entry><literal><link linkend="catalog-pg-authid"><structname>pg_authid</structname></link>.oid</literal></entry>
|
|
<entry>Owner of the operator class</entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry><structfield>opcfamily</structfield></entry>
|
|
<entry><type>oid</type></entry>
|
|
<entry><literal><link linkend="catalog-pg-opfamily"><structname>pg_opfamily</structname></link>.oid</literal></entry>
|
|
<entry>Operator family containing the operator class</entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry><structfield>opcintype</structfield></entry>
|
|
<entry><type>oid</type></entry>
|
|
<entry><literal><link linkend="catalog-pg-type"><structname>pg_type</structname></link>.oid</literal></entry>
|
|
<entry>Data type that the operator class indexes</entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry><structfield>opcdefault</structfield></entry>
|
|
<entry><type>bool</type></entry>
|
|
<entry></entry>
|
|
<entry>True if this operator class is the default for <structfield>opcintype</></entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry><structfield>opckeytype</structfield></entry>
|
|
<entry><type>oid</type></entry>
|
|
<entry><literal><link linkend="catalog-pg-type"><structname>pg_type</structname></link>.oid</literal></entry>
|
|
<entry>Type of data stored in index, or zero if same as <structfield>opcintype</></entry>
|
|
</row>
|
|
|
|
</tbody>
|
|
</tgroup>
|
|
</table>
|
|
|
|
<para>
|
|
An operator class's <structfield>opcmethod</> must match the
|
|
<structname>opfmethod</> of its containing operator family.
|
|
Also, there must be no more than one <structname>pg_opclass</structname>
|
|
row having <structname>opcdefault</> true for any given combination of
|
|
<structname>opcmethod</> and <structname>opcintype</>.
|
|
</para>
|
|
|
|
</sect1>
|
|
|
|
|
|
<sect1 id="catalog-pg-operator">
|
|
<title><structname>pg_operator</structname></title>
|
|
|
|
<indexterm zone="catalog-pg-operator">
|
|
<primary>pg_operator</primary>
|
|
</indexterm>
|
|
|
|
<para>
|
|
The catalog <structname>pg_operator</> stores information about operators.
|
|
See <xref linkend="sql-createoperator" endterm="sql-createoperator-title">
|
|
and <xref linkend="xoper"> for more information.
|
|
</para>
|
|
|
|
<table>
|
|
<title><structname>pg_operator</> Columns</title>
|
|
|
|
<tgroup cols="4">
|
|
<thead>
|
|
<row>
|
|
<entry>Name</entry>
|
|
<entry>Type</entry>
|
|
<entry>References</entry>
|
|
<entry>Description</entry>
|
|
</row>
|
|
</thead>
|
|
|
|
<tbody>
|
|
<row>
|
|
<entry><structfield>oprname</structfield></entry>
|
|
<entry><type>name</type></entry>
|
|
<entry></entry>
|
|
<entry>Name of the operator</entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry><structfield>oprnamespace</structfield></entry>
|
|
<entry><type>oid</type></entry>
|
|
<entry><literal><link linkend="catalog-pg-namespace"><structname>pg_namespace</structname></link>.oid</literal></entry>
|
|
<entry>
|
|
The OID of the namespace that contains this operator
|
|
</entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry><structfield>oprowner</structfield></entry>
|
|
<entry><type>oid</type></entry>
|
|
<entry><literal><link linkend="catalog-pg-authid"><structname>pg_authid</structname></link>.oid</literal></entry>
|
|
<entry>Owner of the operator</entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry><structfield>oprkind</structfield></entry>
|
|
<entry><type>char</type></entry>
|
|
<entry></entry>
|
|
<entry>
|
|
<literal>b</> = infix (<quote>both</quote>), <literal>l</> = prefix
|
|
(<quote>left</quote>), <literal>r</> = postfix (<quote>right</quote>)
|
|
</entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry><structfield>oprcanmerge</structfield></entry>
|
|
<entry><type>bool</type></entry>
|
|
<entry></entry>
|
|
<entry>This operator supports merge joins</entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry><structfield>oprcanhash</structfield></entry>
|
|
<entry><type>bool</type></entry>
|
|
<entry></entry>
|
|
<entry>This operator supports hash joins</entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry><structfield>oprleft</structfield></entry>
|
|
<entry><type>oid</type></entry>
|
|
<entry><literal><link linkend="catalog-pg-type"><structname>pg_type</structname></link>.oid</literal></entry>
|
|
<entry>Type of the left operand</entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry><structfield>oprright</structfield></entry>
|
|
<entry><type>oid</type></entry>
|
|
<entry><literal><link linkend="catalog-pg-type"><structname>pg_type</structname></link>.oid</literal></entry>
|
|
<entry>Type of the right operand</entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry><structfield>oprresult</structfield></entry>
|
|
<entry><type>oid</type></entry>
|
|
<entry><literal><link linkend="catalog-pg-type"><structname>pg_type</structname></link>.oid</literal></entry>
|
|
<entry>Type of the result</entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry><structfield>oprcom</structfield></entry>
|
|
<entry><type>oid</type></entry>
|
|
<entry><literal><link linkend="catalog-pg-operator"><structname>pg_operator</structname></link>.oid</literal></entry>
|
|
<entry>Commutator of this operator, if any</entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry><structfield>oprnegate</structfield></entry>
|
|
<entry><type>oid</type></entry>
|
|
<entry><literal><link linkend="catalog-pg-operator"><structname>pg_operator</structname></link>.oid</literal></entry>
|
|
<entry>Negator of this operator, if any</entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry><structfield>oprcode</structfield></entry>
|
|
<entry><type>regproc</type></entry>
|
|
<entry><literal><link linkend="catalog-pg-proc"><structname>pg_proc</structname></link>.oid</literal></entry>
|
|
<entry>Function that implements this operator</entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry><structfield>oprrest</structfield></entry>
|
|
<entry><type>regproc</type></entry>
|
|
<entry><literal><link linkend="catalog-pg-proc"><structname>pg_proc</structname></link>.oid</literal></entry>
|
|
<entry>Restriction selectivity estimation function for this operator</entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry><structfield>oprjoin</structfield></entry>
|
|
<entry><type>regproc</type></entry>
|
|
<entry><literal><link linkend="catalog-pg-proc"><structname>pg_proc</structname></link>.oid</literal></entry>
|
|
<entry>Join selectivity estimation function for this operator</entry>
|
|
</row>
|
|
</tbody>
|
|
</tgroup>
|
|
</table>
|
|
|
|
<para>
|
|
Unused column contain zeroes. For example, <structfield>oprleft</structfield>
|
|
is zero for a prefix operator.
|
|
</para>
|
|
|
|
</sect1>
|
|
|
|
|
|
<sect1 id="catalog-pg-opfamily">
|
|
<title><structname>pg_opfamily</structname></title>
|
|
|
|
<indexterm zone="catalog-pg-opfamily">
|
|
<primary>pg_opfamily</primary>
|
|
</indexterm>
|
|
|
|
<para>
|
|
The catalog <structname>pg_opfamily</structname> defines operator families.
|
|
Each operator family is a collection of operators and associated
|
|
support routines that implement the semantics specified for a particular
|
|
index access method. Furthermore, the operators in a family are all
|
|
<quote>compatible</>, in a way that is specified by the access method.
|
|
The operator family concept allows cross-data-type operators to be used
|
|
with indexes and to be reasoned about using knowledge of access method
|
|
semantics.
|
|
</para>
|
|
|
|
<para>
|
|
Operator families are described at length in <xref linkend="xindex">.
|
|
</para>
|
|
|
|
<table>
|
|
<title><structname>pg_opfamily</> Columns</title>
|
|
|
|
<tgroup cols="4">
|
|
<thead>
|
|
<row>
|
|
<entry>Name</entry>
|
|
<entry>Type</entry>
|
|
<entry>References</entry>
|
|
<entry>Description</entry>
|
|
</row>
|
|
</thead>
|
|
<tbody>
|
|
|
|
<row>
|
|
<entry><structfield>opfmethod</structfield></entry>
|
|
<entry><type>oid</type></entry>
|
|
<entry><literal><link linkend="catalog-pg-am"><structname>pg_am</structname></link>.oid</literal></entry>
|
|
<entry>Index access method operator family is for</entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry><structfield>opfname</structfield></entry>
|
|
<entry><type>name</type></entry>
|
|
<entry></entry>
|
|
<entry>Name of this operator family</entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry><structfield>opfnamespace</structfield></entry>
|
|
<entry><type>oid</type></entry>
|
|
<entry><literal><link linkend="catalog-pg-namespace"><structname>pg_namespace</structname></link>.oid</literal></entry>
|
|
<entry>Namespace of this operator family</entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry><structfield>opfowner</structfield></entry>
|
|
<entry><type>oid</type></entry>
|
|
<entry><literal><link linkend="catalog-pg-authid"><structname>pg_authid</structname></link>.oid</literal></entry>
|
|
<entry>Owner of the operator family</entry>
|
|
</row>
|
|
|
|
</tbody>
|
|
</tgroup>
|
|
</table>
|
|
|
|
<para>
|
|
The majority of the information defining an operator family is not in its
|
|
<structname>pg_opfamily</structname> row, but in the associated rows in
|
|
<link linkend="catalog-pg-amop"><structname>pg_amop</structname></link>,
|
|
<link linkend="catalog-pg-amproc"><structname>pg_amproc</structname></link>,
|
|
and
|
|
<link linkend="catalog-pg-opclass"><structname>pg_opclass</structname></link>.
|
|
</para>
|
|
|
|
</sect1>
|
|
|
|
|
|
<sect1 id="catalog-pg-pltemplate">
|
|
<title><structname>pg_pltemplate</structname></title>
|
|
|
|
<indexterm zone="catalog-pg-pltemplate">
|
|
<primary>pg_pltemplate</primary>
|
|
</indexterm>
|
|
|
|
<para>
|
|
The catalog <structname>pg_pltemplate</structname> stores
|
|
<quote>template</> information for procedural languages.
|
|
A template for a language allows the language to be created in a
|
|
particular database by a simple <command>CREATE LANGUAGE</> command,
|
|
with no need to specify implementation details.
|
|
</para>
|
|
|
|
<para>
|
|
Unlike most system catalogs, <structname>pg_pltemplate</structname>
|
|
is shared across all databases of a cluster: there is only one
|
|
copy of <structname>pg_pltemplate</structname> per cluster, not
|
|
one per database. This allows the information to be accessible in
|
|
each database as it is needed.
|
|
</para>
|
|
|
|
<table>
|
|
<title><structname>pg_pltemplate</> Columns</title>
|
|
|
|
<tgroup cols="3">
|
|
<thead>
|
|
<row>
|
|
<entry>Name</entry>
|
|
<entry>Type</entry>
|
|
<entry>Description</entry>
|
|
</row>
|
|
</thead>
|
|
|
|
<tbody>
|
|
<row>
|
|
<entry><structfield>tmplname</structfield></entry>
|
|
<entry><type>name</type></entry>
|
|
<entry>Name of the language this template is for</entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry><structfield>tmpltrusted</structfield></entry>
|
|
<entry><type>boolean</type></entry>
|
|
<entry>True if language is considered trusted</entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry><structfield>tmpldbacreate</structfield></entry>
|
|
<entry><type>boolean</type></entry>
|
|
<entry>True if language may be created by a database owner</entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry><structfield>tmplhandler</structfield></entry>
|
|
<entry><type>text</type></entry>
|
|
<entry>Name of call handler function</entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry><structfield>tmplinline</structfield></entry>
|
|
<entry><type>text</type></entry>
|
|
<entry>Name of anonymous-block handler function, or NULL if none</entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry><structfield>tmplvalidator</structfield></entry>
|
|
<entry><type>text</type></entry>
|
|
<entry>Name of validator function, or NULL if none</entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry><structfield>tmpllibrary</structfield></entry>
|
|
<entry><type>text</type></entry>
|
|
<entry>Path of shared library that implements language</entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry><structfield>tmplacl</structfield></entry>
|
|
<entry><type>aclitem[]</type></entry>
|
|
<entry>Access privileges for template (not yet used)</entry>
|
|
</row>
|
|
|
|
</tbody>
|
|
</tgroup>
|
|
</table>
|
|
|
|
<para>
|
|
There are not currently any commands that manipulate procedural language
|
|
templates; to change the built-in information, a superuser must modify
|
|
the table using ordinary <command>INSERT</command>, <command>DELETE</command>,
|
|
or <command>UPDATE</command> commands. It is likely that a future
|
|
release of <productname>PostgreSQL</productname> will offer
|
|
commands to change the entries in a cleaner fashion.
|
|
</para>
|
|
|
|
<para>
|
|
When implemented, the <structfield>tmplacl</structfield> field will provide
|
|
access control for the template itself (i.e., the right to create a
|
|
language using it), not for the languages created from the template.
|
|
</para>
|
|
|
|
</sect1>
|
|
|
|
|
|
<sect1 id="catalog-pg-proc">
|
|
<title><structname>pg_proc</structname></title>
|
|
|
|
<indexterm zone="catalog-pg-proc">
|
|
<primary>pg_proc</primary>
|
|
</indexterm>
|
|
|
|
<para>
|
|
The catalog <structname>pg_proc</> stores information about functions (or procedures).
|
|
See <xref linkend="sql-createfunction" endterm="sql-createfunction-title">
|
|
and <xref linkend="xfunc"> for more information.
|
|
</para>
|
|
|
|
<para>
|
|
The table contains data for aggregate functions as well as plain functions.
|
|
If <structfield>proisagg</structfield> is true, there should be a matching
|
|
row in <structfield>pg_aggregate</structfield>.
|
|
</para>
|
|
|
|
<table>
|
|
<title><structname>pg_proc</> Columns</title>
|
|
|
|
<tgroup cols="4">
|
|
<thead>
|
|
<row>
|
|
<entry>Name</entry>
|
|
<entry>Type</entry>
|
|
<entry>References</entry>
|
|
<entry>Description</entry>
|
|
</row>
|
|
</thead>
|
|
|
|
<tbody>
|
|
<row>
|
|
<entry><structfield>proname</structfield></entry>
|
|
<entry><type>name</type></entry>
|
|
<entry></entry>
|
|
<entry>Name of the function</entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry><structfield>pronamespace</structfield></entry>
|
|
<entry><type>oid</type></entry>
|
|
<entry><literal><link linkend="catalog-pg-namespace"><structname>pg_namespace</structname></link>.oid</literal></entry>
|
|
<entry>
|
|
The OID of the namespace that contains this function
|
|
</entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry><structfield>proowner</structfield></entry>
|
|
<entry><type>oid</type></entry>
|
|
<entry><literal><link linkend="catalog-pg-authid"><structname>pg_authid</structname></link>.oid</literal></entry>
|
|
<entry>Owner of the function</entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry><structfield>prolang</structfield></entry>
|
|
<entry><type>oid</type></entry>
|
|
<entry><literal><link linkend="catalog-pg-language"><structname>pg_language</structname></link>.oid</literal></entry>
|
|
<entry>Implementation language or call interface of this function</entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry><structfield>procost</structfield></entry>
|
|
<entry><type>float4</type></entry>
|
|
<entry></entry>
|
|
<entry>Estimated execution cost (in units of
|
|
<xref linkend="guc-cpu-operator-cost">); if <structfield>proretset</>,
|
|
this is cost per row returned</entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry><structfield>prorows</structfield></entry>
|
|
<entry><type>float4</type></entry>
|
|
<entry></entry>
|
|
<entry>Estimated number of result rows (zero if not <structfield>proretset</>)</entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry><structfield>provariadic</structfield></entry>
|
|
<entry><type>oid</type></entry>
|
|
<entry><literal><link linkend="catalog-pg-type"><structname>pg_type</structname></link>.oid</literal></entry>
|
|
<entry>Data type of the variadic array parameter's elements,
|
|
or zero if the function does not have a variadic parameter</entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry><structfield>proisagg</structfield></entry>
|
|
<entry><type>bool</type></entry>
|
|
<entry></entry>
|
|
<entry>Function is an aggregate function</entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry><structfield>proiswindow</structfield></entry>
|
|
<entry><type>bool</type></entry>
|
|
<entry></entry>
|
|
<entry>Function is a window function</entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry><structfield>prosecdef</structfield></entry>
|
|
<entry><type>bool</type></entry>
|
|
<entry></entry>
|
|
<entry>Function is a security definer (i.e., a <quote>setuid</>
|
|
function)</entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry><structfield>proisstrict</structfield></entry>
|
|
<entry><type>bool</type></entry>
|
|
<entry></entry>
|
|
<entry>
|
|
Function returns null if any call argument is null. In that
|
|
case the function won't actually be called at all. Functions
|
|
that are not <quote>strict</quote> must be prepared to handle
|
|
null inputs
|
|
</entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry><structfield>proretset</structfield></entry>
|
|
<entry><type>bool</type></entry>
|
|
<entry></entry>
|
|
<entry>Function returns a set (i.e., multiple values of the specified
|
|
data type)</entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry><structfield>provolatile</structfield></entry>
|
|
<entry><type>char</type></entry>
|
|
<entry></entry>
|
|
<entry>
|
|
<structfield>provolatile</structfield> tells whether the function's
|
|
result depends only on its input arguments, or is affected by outside
|
|
factors.
|
|
It is <literal>i</literal> for <quote>immutable</> functions,
|
|
which always deliver the same result for the same inputs.
|
|
It is <literal>s</literal> for <quote>stable</> functions,
|
|
whose results (for fixed inputs) do not change within a scan.
|
|
It is <literal>v</literal> for <quote>volatile</> functions,
|
|
whose results might change at any time. (Use <literal>v</literal> also
|
|
for functions with side-effects, so that calls to them cannot get
|
|
optimized away.)
|
|
</entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry><structfield>pronargs</structfield></entry>
|
|
<entry><type>int2</type></entry>
|
|
<entry></entry>
|
|
<entry>Number of input arguments</entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry><structfield>pronargdefaults</structfield></entry>
|
|
<entry><type>int2</type></entry>
|
|
<entry></entry>
|
|
<entry>Number of arguments that have defaults</entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry><structfield>prorettype</structfield></entry>
|
|
<entry><type>oid</type></entry>
|
|
<entry><literal><link linkend="catalog-pg-type"><structname>pg_type</structname></link>.oid</literal></entry>
|
|
<entry>Data type of the return value</entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry><structfield>proargtypes</structfield></entry>
|
|
<entry><type>oidvector</type></entry>
|
|
<entry><literal><link linkend="catalog-pg-type"><structname>pg_type</structname></link>.oid</literal></entry>
|
|
<entry>
|
|
An array with the data types of the function arguments. This includes
|
|
only input arguments (including <literal>INOUT</literal> and
|
|
<literal>VARIADIC</> arguments), and thus represents
|
|
the call signature of the function
|
|
</entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry><structfield>proallargtypes</structfield></entry>
|
|
<entry><type>oid[]</type></entry>
|
|
<entry><literal><link linkend="catalog-pg-type"><structname>pg_type</structname></link>.oid</literal></entry>
|
|
<entry>
|
|
An array with the data types of the function arguments. This includes
|
|
all arguments (including <literal>OUT</literal> and
|
|
<literal>INOUT</literal> arguments); however, if all the
|
|
arguments are <literal>IN</literal> arguments, this field will be null.
|
|
Note that subscripting is 1-based, whereas for historical reasons
|
|
<structfield>proargtypes</> is subscripted from 0
|
|
</entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry><structfield>proargmodes</structfield></entry>
|
|
<entry><type>char[]</type></entry>
|
|
<entry></entry>
|
|
<entry>
|
|
An array with the modes of the function arguments, encoded as
|
|
<literal>i</literal> for <literal>IN</> arguments,
|
|
<literal>o</literal> for <literal>OUT</> arguments,
|
|
<literal>b</literal> for <literal>INOUT</> arguments,
|
|
<literal>v</literal> for <literal>VARIADIC</> arguments,
|
|
<literal>t</literal> for <literal>TABLE</> arguments.
|
|
If all the arguments are <literal>IN</literal> arguments,
|
|
this field will be null.
|
|
Note that subscripts correspond to positions of
|
|
<structfield>proallargtypes</> not <structfield>proargtypes</>
|
|
</entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry><structfield>proargnames</structfield></entry>
|
|
<entry><type>text[]</type></entry>
|
|
<entry></entry>
|
|
<entry>
|
|
An array with the names of the function arguments.
|
|
Arguments without a name are set to empty strings in the array.
|
|
If none of the arguments have a name, this field will be null.
|
|
Note that subscripts correspond to positions of
|
|
<structfield>proallargtypes</> not <structfield>proargtypes</>
|
|
</entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry><structfield>proargdefaults</structfield></entry>
|
|
<entry><type>text</type></entry>
|
|
<entry></entry>
|
|
<entry>
|
|
Expression trees (in <function>nodeToString()</function> representation)
|
|
for default values. This is a list with
|
|
<structfield>pronargdefaults</> elements, corresponding to the last
|
|
<replaceable>N</> <emphasis>input</> arguments (i.e., the last
|
|
<replaceable>N</> <structfield>proargtypes</> positions).
|
|
If none of the arguments have defaults, this field will be null
|
|
</entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry><structfield>prosrc</structfield></entry>
|
|
<entry><type>text</type></entry>
|
|
<entry></entry>
|
|
<entry>
|
|
This tells the function handler how to invoke the function. It
|
|
might be the actual source code of the function for interpreted
|
|
languages, a link symbol, a file name, or just about anything
|
|
else, depending on the implementation language/call convention
|
|
</entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry><structfield>probin</structfield></entry>
|
|
<entry><type>text</type></entry>
|
|
<entry></entry>
|
|
<entry>
|
|
Additional information about how to invoke the function.
|
|
Again, the interpretation is language-specific
|
|
</entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry><structfield>proconfig</structfield></entry>
|
|
<entry><type>text[]</type></entry>
|
|
<entry></entry>
|
|
<entry>Function's local settings for run-time configuration variables</entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry><structfield>proacl</structfield></entry>
|
|
<entry><type>aclitem[]</type></entry>
|
|
<entry></entry>
|
|
<entry>
|
|
Access privileges; see
|
|
<xref linkend="sql-grant" endterm="sql-grant-title"> and
|
|
<xref linkend="sql-revoke" endterm="sql-revoke-title">
|
|
for details
|
|
</entry>
|
|
</row>
|
|
</tbody>
|
|
</tgroup>
|
|
</table>
|
|
|
|
<para>
|
|
For compiled functions, both built-in and dynamically loaded,
|
|
<structfield>prosrc</structfield> contains the function's C-language
|
|
name (link symbol). For all other currently-known language types,
|
|
<structfield>prosrc</structfield> contains the function's source
|
|
text. <structfield>probin</structfield> is unused except for
|
|
dynamically-loaded C functions, for which it gives the name of the
|
|
shared library file containing the function.
|
|
</para>
|
|
|
|
</sect1>
|
|
|
|
<sect1 id="catalog-pg-rewrite">
|
|
<title><structname>pg_rewrite</structname></title>
|
|
|
|
<indexterm zone="catalog-pg-rewrite">
|
|
<primary>pg_rewrite</primary>
|
|
</indexterm>
|
|
|
|
<para>
|
|
The catalog <structname>pg_rewrite</structname> stores rewrite rules for tables and views.
|
|
</para>
|
|
|
|
<table>
|
|
<title><structname>pg_rewrite</> Columns</title>
|
|
|
|
<tgroup cols="4">
|
|
<thead>
|
|
<row>
|
|
<entry>Name</entry>
|
|
<entry>Type</entry>
|
|
<entry>References</entry>
|
|
<entry>Description</entry>
|
|
</row>
|
|
</thead>
|
|
|
|
<tbody>
|
|
<row>
|
|
<entry><structfield>rulename</structfield></entry>
|
|
<entry><type>name</type></entry>
|
|
<entry></entry>
|
|
<entry>Rule name</entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry><structfield>ev_class</structfield></entry>
|
|
<entry><type>oid</type></entry>
|
|
<entry><literal><link linkend="catalog-pg-class"><structname>pg_class</structname></link>.oid</literal></entry>
|
|
<entry>The table this rule is for</entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry><structfield>ev_attr</structfield></entry>
|
|
<entry><type>int2</type></entry>
|
|
<entry></entry>
|
|
<entry>The column this rule is for (currently, always zero to
|
|
indicate the whole table)</entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry><structfield>ev_type</structfield></entry>
|
|
<entry><type>char</type></entry>
|
|
<entry></entry>
|
|
<entry>
|
|
Event type that the rule is for: 1 = <command>SELECT</>, 2 =
|
|
<command>UPDATE</>, 3 = <command>INSERT</>, 4 =
|
|
<command>DELETE</>
|
|
</entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry><structfield>ev_enabled</structfield></entry>
|
|
<entry><type>char</type></entry>
|
|
<entry></entry>
|
|
<entry>
|
|
Controls in which <xref linkend="guc-session-replication-role"> modes
|
|
the rule fires.
|
|
<literal>O</> = rule fires in <quote>origin</> and <quote>local</> modes,
|
|
<literal>D</> = rule is disabled,
|
|
<literal>R</> = rule fires in <quote>replica</> mode,
|
|
<literal>A</> = rule fires always.
|
|
</entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry><structfield>is_instead</structfield></entry>
|
|
<entry><type>bool</type></entry>
|
|
<entry></entry>
|
|
<entry>True if the rule is an <literal>INSTEAD</literal> rule</entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry><structfield>ev_qual</structfield></entry>
|
|
<entry><type>text</type></entry>
|
|
<entry></entry>
|
|
<entry>
|
|
Expression tree (in the form of a
|
|
<function>nodeToString()</function> representation) for the
|
|
rule's qualifying condition
|
|
</entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry><structfield>ev_action</structfield></entry>
|
|
<entry><type>text</type></entry>
|
|
<entry></entry>
|
|
<entry>
|
|
Query tree (in the form of a
|
|
<function>nodeToString()</function> representation) for the
|
|
rule's action
|
|
</entry>
|
|
</row>
|
|
</tbody>
|
|
</tgroup>
|
|
</table>
|
|
|
|
<note>
|
|
<para>
|
|
<literal>pg_class.relhasrules</literal>
|
|
must be true if a table has any rules in this catalog.
|
|
</para>
|
|
</note>
|
|
|
|
</sect1>
|
|
|
|
<sect1 id="catalog-pg-db-role-setting">
|
|
<title><structname>pg_db_role_setting</structname></title>
|
|
|
|
<indexterm zone="catalog-pg-db-role-setting">
|
|
<primary>pg_db_role_setting</primary>
|
|
</indexterm>
|
|
|
|
<para>
|
|
The catalog <structname>pg_db_role_setting</structname> records the default
|
|
values that have been set for run-time configuration variables,
|
|
for each role and database combination.
|
|
</para>
|
|
|
|
<para>
|
|
Unlike most system catalogs, <structname>pg_db_role_setting</structname>
|
|
is shared across all databases of a cluster: there is only one
|
|
copy of <structname>pg_db_role_setting</structname> per cluster, not
|
|
one per database.
|
|
</para>
|
|
|
|
<table>
|
|
<title><structname>pg_db_role_setting</> Columns</title>
|
|
|
|
<tgroup cols="4">
|
|
<thead>
|
|
<row>
|
|
<entry>Name</entry>
|
|
<entry>Type</entry>
|
|
<entry>References</entry>
|
|
<entry>Description</entry>
|
|
</row>
|
|
</thead>
|
|
|
|
<tbody>
|
|
<row>
|
|
<entry><structfield>setdatabase</structfield></entry>
|
|
<entry><type>oid</type></entry>
|
|
<entry><literal><link linkend="catalog-pg-database"><structname>pg_database</structname></link>.oid</literal></entry>
|
|
<entry>The OID of the database the setting is applicable to, or zero if not database-specific</entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry><structfield>setrole</structfield></entry>
|
|
<entry><type>oid</type></entry>
|
|
<entry><literal><link linkend="catalog-pg-authid"><structname>pg_authid</structname></link>.oid</literal></entry>
|
|
<entry>The OID of the role the setting is applicable to, or zero if not role-specific</entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry><structfield>setconfig</structfield></entry>
|
|
<entry><type>text[]</type></entry>
|
|
<entry></entry>
|
|
<entry>Defaults for run-time configuration variables</entry>
|
|
</row>
|
|
</tbody>
|
|
</tgroup>
|
|
</table>
|
|
</sect1>
|
|
|
|
|
|
<sect1 id="catalog-pg-shdepend">
|
|
<title><structname>pg_shdepend</structname></title>
|
|
|
|
<indexterm zone="catalog-pg-shdepend">
|
|
<primary>pg_shdepend</primary>
|
|
</indexterm>
|
|
|
|
<para>
|
|
The catalog <structname>pg_shdepend</structname> records the
|
|
dependency relationships between database objects and shared objects,
|
|
such as roles. This information allows
|
|
<productname>PostgreSQL</productname> to ensure that those objects are
|
|
unreferenced before attempting to delete them.
|
|
</para>
|
|
|
|
<para>
|
|
See also <link linkend="catalog-pg-depend"><structname>pg_depend</structname></link>,
|
|
which performs a similar function for dependencies involving objects
|
|
within a single database.
|
|
</para>
|
|
|
|
<para>
|
|
Unlike most system catalogs, <structname>pg_shdepend</structname>
|
|
is shared across all databases of a cluster: there is only one
|
|
copy of <structname>pg_shdepend</structname> per cluster, not
|
|
one per database.
|
|
</para>
|
|
|
|
<table>
|
|
<title><structname>pg_shdepend</> Columns</title>
|
|
|
|
<tgroup cols="4">
|
|
<thead>
|
|
<row>
|
|
<entry>Name</entry>
|
|
<entry>Type</entry>
|
|
<entry>References</entry>
|
|
<entry>Description</entry>
|
|
</row>
|
|
</thead>
|
|
|
|
<tbody>
|
|
<row>
|
|
<entry><structfield>dbid</structfield></entry>
|
|
<entry><type>oid</type></entry>
|
|
<entry><literal><link linkend="catalog-pg-database"><structname>pg_database</structname></link>.oid</literal></entry>
|
|
<entry>The OID of the database the dependent object is in,
|
|
or zero for a shared object</entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry><structfield>classid</structfield></entry>
|
|
<entry><type>oid</type></entry>
|
|
<entry><literal><link linkend="catalog-pg-class"><structname>pg_class</structname></link>.oid</literal></entry>
|
|
<entry>The OID of the system catalog the dependent object is in</entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry><structfield>objid</structfield></entry>
|
|
<entry><type>oid</type></entry>
|
|
<entry>any OID column</entry>
|
|
<entry>The OID of the specific dependent object</entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry><structfield>objsubid</structfield></entry>
|
|
<entry><type>int4</type></entry>
|
|
<entry></entry>
|
|
<entry>
|
|
For a table column, this is the column number (the
|
|
<structfield>objid</> and <structfield>classid</> refer to the
|
|
table itself). For all other object types, this column is zero
|
|
</entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry><structfield>refclassid</structfield></entry>
|
|
<entry><type>oid</type></entry>
|
|
<entry><literal><link linkend="catalog-pg-class"><structname>pg_class</structname></link>.oid</literal></entry>
|
|
<entry>The OID of the system catalog the referenced object is in
|
|
(must be a shared catalog)</entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry><structfield>refobjid</structfield></entry>
|
|
<entry><type>oid</type></entry>
|
|
<entry>any OID column</entry>
|
|
<entry>The OID of the specific referenced object</entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry><structfield>deptype</structfield></entry>
|
|
<entry><type>char</type></entry>
|
|
<entry></entry>
|
|
<entry>
|
|
A code defining the specific semantics of this dependency relationship; see text
|
|
</entry>
|
|
</row>
|
|
|
|
</tbody>
|
|
</tgroup>
|
|
</table>
|
|
|
|
<para>
|
|
In all cases, a <structname>pg_shdepend</structname> entry indicates that
|
|
the referenced object cannot be dropped without also dropping the dependent
|
|
object. However, there are several subflavors identified by
|
|
<structfield>deptype</>:
|
|
|
|
<variablelist>
|
|
<varlistentry>
|
|
<term><symbol>SHARED_DEPENDENCY_OWNER</> (<literal>o</>)</term>
|
|
<listitem>
|
|
<para>
|
|
The referenced object (which must be a role) is the owner of the
|
|
dependent object.
|
|
</para>
|
|
</listitem>
|
|
</varlistentry>
|
|
|
|
<varlistentry>
|
|
<term><symbol>SHARED_DEPENDENCY_ACL</> (<literal>a</>)</term>
|
|
<listitem>
|
|
<para>
|
|
The referenced object (which must be a role) is mentioned in the
|
|
ACL (access control list, i.e., privileges list) of the
|
|
dependent object. (A <symbol>SHARED_DEPENDENCY_ACL</> entry is
|
|
not made for the owner of the object, since the owner will have
|
|
a <symbol>SHARED_DEPENDENCY_OWNER</> entry anyway.)
|
|
</para>
|
|
</listitem>
|
|
</varlistentry>
|
|
|
|
<varlistentry>
|
|
<term><symbol>SHARED_DEPENDENCY_PIN</> (<literal>p</>)</term>
|
|
<listitem>
|
|
<para>
|
|
There is no dependent object; this type of entry is a signal
|
|
that the system itself depends on the referenced object, and so
|
|
that object must never be deleted. Entries of this type are
|
|
created only by <command>initdb</command>. The columns for the
|
|
dependent object contain zeroes.
|
|
</para>
|
|
</listitem>
|
|
</varlistentry>
|
|
</variablelist>
|
|
|
|
Other dependency flavors might be needed in future. Note in particular
|
|
that the current definition only supports roles as referenced objects.
|
|
</para>
|
|
|
|
</sect1>
|
|
|
|
<sect1 id="catalog-pg-shdescription">
|
|
<title><structname>pg_shdescription</structname></title>
|
|
|
|
<indexterm zone="catalog-pg-shdescription">
|
|
<primary>pg_shdescription</primary>
|
|
</indexterm>
|
|
|
|
<para>
|
|
The catalog <structname>pg_shdescription</structname> stores optional
|
|
descriptions (comments) for shared database objects. Descriptions can be
|
|
manipulated with the <xref linkend="sql-comment"
|
|
endterm="sql-comment-title"> command and viewed with
|
|
<application>psql</application>'s <literal>\d</literal> commands.
|
|
</para>
|
|
|
|
<para>
|
|
See also <link linkend="catalog-pg-description"><structname>pg_description</structname></link>,
|
|
which performs a similar function for descriptions involving objects
|
|
within a single database.
|
|
</para>
|
|
|
|
<para>
|
|
Unlike most system catalogs, <structname>pg_shdescription</structname>
|
|
is shared across all databases of a cluster: there is only one
|
|
copy of <structname>pg_shdescription</structname> per cluster, not
|
|
one per database.
|
|
</para>
|
|
|
|
<table>
|
|
<title><structname>pg_shdescription</> Columns</title>
|
|
|
|
<tgroup cols="4">
|
|
<thead>
|
|
<row>
|
|
<entry>Name</entry>
|
|
<entry>Type</entry>
|
|
<entry>References</entry>
|
|
<entry>Description</entry>
|
|
</row>
|
|
</thead>
|
|
|
|
<tbody>
|
|
<row>
|
|
<entry><structfield>objoid</structfield></entry>
|
|
<entry><type>oid</type></entry>
|
|
<entry>any OID column</entry>
|
|
<entry>The OID of the object this description pertains to</entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry><structfield>classoid</structfield></entry>
|
|
<entry><type>oid</type></entry>
|
|
<entry><literal><link linkend="catalog-pg-class"><structname>pg_class</structname></link>.oid</literal></entry>
|
|
<entry>The OID of the system catalog this object appears in</entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry><structfield>description</structfield></entry>
|
|
<entry><type>text</type></entry>
|
|
<entry></entry>
|
|
<entry>Arbitrary text that serves as the description of this object</entry>
|
|
</row>
|
|
</tbody>
|
|
</tgroup>
|
|
</table>
|
|
|
|
</sect1>
|
|
|
|
|
|
<sect1 id="catalog-pg-statistic">
|
|
<title><structname>pg_statistic</structname></title>
|
|
|
|
<indexterm zone="catalog-pg-statistic">
|
|
<primary>pg_statistic</primary>
|
|
</indexterm>
|
|
|
|
<para>
|
|
The catalog <structname>pg_statistic</structname> stores
|
|
statistical data about the contents of the database. Entries are
|
|
created by <xref linkend="sql-analyze" endterm="sql-analyze-title">
|
|
and subsequently used by the query planner. Note that all the
|
|
statistical data is inherently approximate, even assuming that it
|
|
is up-to-date.
|
|
</para>
|
|
|
|
<para>
|
|
Normally there is one entry, with <structfield>stainherit</> =
|
|
<literal>false</>, for each table column that has been analyzed.
|
|
If the table has inheritance children, a second entry with
|
|
<structfield>stainherit</> = <literal>true</> is also created. This row
|
|
represents the column's statistics over the inheritance tree, i.e.,
|
|
statistics for the data you'd see with
|
|
<literal>SELECT <replaceable>column</> FROM <replaceable>table</>*</literal>,
|
|
whereas the <structfield>stainherit</> = <literal>false</> row represents
|
|
the results of
|
|
<literal>SELECT <replaceable>column</> FROM ONLY <replaceable>table</></literal>.
|
|
</para>
|
|
|
|
<para>
|
|
<structname>pg_statistic</structname> also stores statistical data about
|
|
the values of index expressions. These are described as if they were
|
|
actual data columns; in particular, <structfield>starelid</structfield>
|
|
references the index. No entry is made for an ordinary non-expression
|
|
index column, however, since it would be redundant with the entry
|
|
for the underlying table column. Currently, entries for index expressions
|
|
always have <structfield>stainherit</> = <literal>false</>.
|
|
</para>
|
|
|
|
<para>
|
|
Since different kinds of statistics might be appropriate for different
|
|
kinds of data, <structname>pg_statistic</structname> is designed not
|
|
to assume very much about what sort of statistics it stores. Only
|
|
extremely general statistics (such as nullness) are given dedicated
|
|
columns in <structname>pg_statistic</structname>. Everything else
|
|
is stored in <quote>slots</quote>, which are groups of associated columns
|
|
whose content is identified by a code number in one of the slot's columns.
|
|
For more information see
|
|
<filename>src/include/catalog/pg_statistic.h</filename>.
|
|
</para>
|
|
|
|
<para>
|
|
<structname>pg_statistic</structname> should not be readable by the
|
|
public, since even statistical information about a table's contents
|
|
might be considered sensitive. (Example: minimum and maximum values
|
|
of a salary column might be quite interesting.)
|
|
<link linkend="view-pg-stats"><structname>pg_stats</structname></link>
|
|
is a publicly readable view on
|
|
<structname>pg_statistic</structname> that only exposes information
|
|
about those tables that are readable by the current user.
|
|
</para>
|
|
|
|
<table>
|
|
<title><structname>pg_statistic</> Columns</title>
|
|
|
|
<tgroup cols="4">
|
|
<thead>
|
|
<row>
|
|
<entry>Name</entry>
|
|
<entry>Type</entry>
|
|
<entry>References</entry>
|
|
<entry>Description</entry>
|
|
</row>
|
|
</thead>
|
|
|
|
<tbody>
|
|
<row>
|
|
<entry><structfield>starelid</structfield></entry>
|
|
<entry><type>oid</type></entry>
|
|
<entry><literal><link linkend="catalog-pg-class"><structname>pg_class</structname></link>.oid</literal></entry>
|
|
<entry>The table or index that the described column belongs to</entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry><structfield>staattnum</structfield></entry>
|
|
<entry><type>int2</type></entry>
|
|
<entry><literal><link linkend="catalog-pg-attribute"><structname>pg_attribute</structname></link>.attnum</literal></entry>
|
|
<entry>The number of the described column</entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry><structfield>stainherit</structfield></entry>
|
|
<entry><type>bool</type></entry>
|
|
<entry></entry>
|
|
<entry>If true, the stats include inheritance child columns, not just the
|
|
values in the specified relation</entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry><structfield>stanullfrac</structfield></entry>
|
|
<entry><type>float4</type></entry>
|
|
<entry></entry>
|
|
<entry>The fraction of the column's entries that are null</entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry><structfield>stawidth</structfield></entry>
|
|
<entry><type>int4</type></entry>
|
|
<entry></entry>
|
|
<entry>The average stored width, in bytes, of nonnull entries</entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry><structfield>stadistinct</structfield></entry>
|
|
<entry><type>float4</type></entry>
|
|
<entry></entry>
|
|
<entry>The number of distinct nonnull data values in the column.
|
|
A value greater than zero is the actual number of distinct values.
|
|
A value less than zero is the negative of a multiplier for the number
|
|
of rows in the table; for example, a column in which values appear about
|
|
twice on the average could be represented by
|
|
<structfield>stadistinct</> = -0.5.
|
|
A zero value means the number of distinct values is unknown
|
|
</entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry><structfield>stakind<replaceable>N</></structfield></entry>
|
|
<entry><type>int2</type></entry>
|
|
<entry></entry>
|
|
<entry>
|
|
A code number indicating the kind of statistics stored in the
|
|
<replaceable>N</>th <quote>slot</quote> of the
|
|
<structname>pg_statistic</structname> row
|
|
</entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry><structfield>staop<replaceable>N</></structfield></entry>
|
|
<entry><type>oid</type></entry>
|
|
<entry><literal><link linkend="catalog-pg-operator"><structname>pg_operator</structname></link>.oid</literal></entry>
|
|
<entry>
|
|
An operator used to derive the statistics stored in the
|
|
<replaceable>N</>th <quote>slot</quote>. For example, a
|
|
histogram slot would show the <literal><</literal> operator
|
|
that defines the sort order of the data
|
|
</entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry><structfield>stanumbers<replaceable>N</></structfield></entry>
|
|
<entry><type>float4[]</type></entry>
|
|
<entry></entry>
|
|
<entry>
|
|
Numerical statistics of the appropriate kind for the
|
|
<replaceable>N</>th <quote>slot</quote>, or NULL if the slot
|
|
kind does not involve numerical values
|
|
</entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry><structfield>stavalues<replaceable>N</></structfield></entry>
|
|
<entry><type>anyarray</type></entry>
|
|
<entry></entry>
|
|
<entry>
|
|
Column data values of the appropriate kind for the
|
|
<replaceable>N</>th <quote>slot</quote>, or NULL if the slot
|
|
kind does not store any data values. Each array's element
|
|
values are actually of the specific column's data type, so there
|
|
is no way to define these columns' type more specifically than
|
|
<type>anyarray</>
|
|
</entry>
|
|
</row>
|
|
</tbody>
|
|
</tgroup>
|
|
</table>
|
|
|
|
</sect1>
|
|
|
|
|
|
<sect1 id="catalog-pg-tablespace">
|
|
<title><structname>pg_tablespace</structname></title>
|
|
|
|
<indexterm zone="catalog-pg-tablespace">
|
|
<primary>pg_tablespace</primary>
|
|
</indexterm>
|
|
|
|
<para>
|
|
The catalog <structname>pg_tablespace</structname> stores information
|
|
about the available tablespaces. Tables can be placed in particular
|
|
tablespaces to aid administration of disk layout.
|
|
</para>
|
|
|
|
<para>
|
|
Unlike most system catalogs, <structname>pg_tablespace</structname>
|
|
is shared across all databases of a cluster: there is only one
|
|
copy of <structname>pg_tablespace</structname> per cluster, not
|
|
one per database.
|
|
</para>
|
|
|
|
<table>
|
|
<title><structname>pg_tablespace</> Columns</title>
|
|
|
|
<tgroup cols="4">
|
|
<thead>
|
|
<row>
|
|
<entry>Name</entry>
|
|
<entry>Type</entry>
|
|
<entry>References</entry>
|
|
<entry>Description</entry>
|
|
</row>
|
|
</thead>
|
|
|
|
<tbody>
|
|
<row>
|
|
<entry><structfield>spcname</structfield></entry>
|
|
<entry><type>name</type></entry>
|
|
<entry></entry>
|
|
<entry>Tablespace name</entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry><structfield>spcowner</structfield></entry>
|
|
<entry><type>oid</type></entry>
|
|
<entry><literal><link linkend="catalog-pg-authid"><structname>pg_authid</structname></link>.oid</literal></entry>
|
|
<entry>Owner of the tablespace, usually the user who created it</entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry><structfield>spclocation</structfield></entry>
|
|
<entry><type>text</type></entry>
|
|
<entry></entry>
|
|
<entry>Location (directory path) of the tablespace</entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry><structfield>spcacl</structfield></entry>
|
|
<entry><type>aclitem[]</type></entry>
|
|
<entry></entry>
|
|
<entry>
|
|
Access privileges; see
|
|
<xref linkend="sql-grant" endterm="sql-grant-title"> and
|
|
<xref linkend="sql-revoke" endterm="sql-revoke-title">
|
|
for details
|
|
</entry>
|
|
</row>
|
|
</tbody>
|
|
</tgroup>
|
|
</table>
|
|
</sect1>
|
|
|
|
|
|
<sect1 id="catalog-pg-trigger">
|
|
<title><structname>pg_trigger</structname></title>
|
|
|
|
<indexterm zone="catalog-pg-trigger">
|
|
<primary>pg_trigger</primary>
|
|
</indexterm>
|
|
|
|
<para>
|
|
The catalog <structname>pg_trigger</structname> stores triggers on tables.
|
|
See <xref linkend="sql-createtrigger" endterm="sql-createtrigger-title">
|
|
for more information.
|
|
</para>
|
|
|
|
<table>
|
|
<title><structname>pg_trigger</> Columns</title>
|
|
|
|
<tgroup cols="4">
|
|
<thead>
|
|
<row>
|
|
<entry>Name</entry>
|
|
<entry>Type</entry>
|
|
<entry>References</entry>
|
|
<entry>Description</entry>
|
|
</row>
|
|
</thead>
|
|
|
|
<tbody>
|
|
<row>
|
|
<entry><structfield>tgrelid</structfield></entry>
|
|
<entry><type>oid</type></entry>
|
|
<entry><literal><link linkend="catalog-pg-class"><structname>pg_class</structname></link>.oid</literal></entry>
|
|
<entry>The table this trigger is on</entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry><structfield>tgname</structfield></entry>
|
|
<entry><type>name</type></entry>
|
|
<entry></entry>
|
|
<entry>Trigger name (must be unique among triggers of same table)</entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry><structfield>tgfoid</structfield></entry>
|
|
<entry><type>oid</type></entry>
|
|
<entry><literal><link linkend="catalog-pg-proc"><structname>pg_proc</structname></link>.oid</literal></entry>
|
|
<entry>The function to be called</entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry><structfield>tgtype</structfield></entry>
|
|
<entry><type>int2</type></entry>
|
|
<entry></entry>
|
|
<entry>Bit mask identifying trigger conditions</entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry><structfield>tgenabled</structfield></entry>
|
|
<entry><type>char</type></entry>
|
|
<entry></entry>
|
|
<entry>
|
|
Controls in which <xref linkend="guc-session-replication-role"> modes
|
|
the trigger fires.
|
|
<literal>O</> = trigger fires in <quote>origin</> and <quote>local</> modes,
|
|
<literal>D</> = trigger is disabled,
|
|
<literal>R</> = trigger fires in <quote>replica</> mode,
|
|
<literal>A</> = trigger fires always.
|
|
</entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry><structfield>tgisconstraint</structfield></entry>
|
|
<entry><type>bool</type></entry>
|
|
<entry></entry>
|
|
<entry>True if trigger is a <quote>constraint trigger</></entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry><structfield>tgconstrname</structfield></entry>
|
|
<entry><type>name</type></entry>
|
|
<entry></entry>
|
|
<entry>Constraint name, if a constraint trigger</entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry><structfield>tgconstrrelid</structfield></entry>
|
|
<entry><type>oid</type></entry>
|
|
<entry><literal><link linkend="catalog-pg-class"><structname>pg_class</structname></link>.oid</literal></entry>
|
|
<entry>The table referenced by a referential integrity constraint</entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry><structfield>tgconstrindid</structfield></entry>
|
|
<entry><type>oid</type></entry>
|
|
<entry><literal><link linkend="catalog-pg-class"><structname>pg_class</structname></link>.oid</literal></entry>
|
|
<entry>The index supporting a unique, primary key, or referential integrity constraint</entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry><structfield>tgconstraint</structfield></entry>
|
|
<entry><type>oid</type></entry>
|
|
<entry><literal><link linkend="catalog-pg-constraint"><structname>pg_constraint</structname></link>.oid</literal></entry>
|
|
<entry>The <structname>pg_constraint</> entry owning the trigger, if any</entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry><structfield>tgdeferrable</structfield></entry>
|
|
<entry><type>bool</type></entry>
|
|
<entry></entry>
|
|
<entry>True if constraint trigger is deferrable</entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry><structfield>tginitdeferred</structfield></entry>
|
|
<entry><type>bool</type></entry>
|
|
<entry></entry>
|
|
<entry>True if constraint trigger is initially deferred</entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry><structfield>tgnargs</structfield></entry>
|
|
<entry><type>int2</type></entry>
|
|
<entry></entry>
|
|
<entry>Number of argument strings passed to trigger function</entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry><structfield>tgattr</structfield></entry>
|
|
<entry><type>int2vector</type></entry>
|
|
<entry><literal><link linkend="catalog-pg-attribute"><structname>pg_attribute</structname></link>.attnum</literal></entry>
|
|
<entry>column numbers, if trigger is column-specific; otherwise an
|
|
empty array</entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry><structfield>tgargs</structfield></entry>
|
|
<entry><type>bytea</type></entry>
|
|
<entry></entry>
|
|
<entry>Argument strings to pass to trigger, each NULL-terminated</entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry><structfield>tgqual</structfield></entry>
|
|
<entry><type>text</type></entry>
|
|
<entry></entry>
|
|
<entry>Expression tree (in <function>nodeToString()</function>
|
|
representation) for the trigger's <literal>WHEN</> condition, or NULL
|
|
if none</entry>
|
|
</row>
|
|
</tbody>
|
|
</tgroup>
|
|
</table>
|
|
|
|
<para>
|
|
Currently, column-specific triggering is supported only for
|
|
<literal>UPDATE</> events, and so <structfield>tgattr</> is relevant
|
|
only for that event type. <structfield>tgtype</structfield> might
|
|
contain bits for other event types as well, but those are presumed
|
|
to be table-wide regardless of what is in <structfield>tgattr</>.
|
|
</para>
|
|
|
|
<note>
|
|
<para>
|
|
When <structfield>tgconstraint</> is nonzero,
|
|
<structfield>tgisconstraint</> must be true, and
|
|
<structfield>tgconstrname</>, <structfield>tgconstrrelid</>,
|
|
<structfield>tgconstrindid</>,
|
|
<structfield>tgdeferrable</>, <structfield>tginitdeferred</> are redundant
|
|
with the referenced <structname>pg_constraint</> entry. The reason we
|
|
keep these fields is that we support <quote>stand-alone</> constraint
|
|
triggers with no corresponding <structname>pg_constraint</> entry.
|
|
</para>
|
|
</note>
|
|
|
|
<note>
|
|
<para>
|
|
<literal>pg_class.relhastriggers</literal>
|
|
must be true if a table has any triggers in this catalog.
|
|
</para>
|
|
</note>
|
|
|
|
</sect1>
|
|
|
|
|
|
<sect1 id="catalog-pg-ts-config">
|
|
<title><structname>pg_ts_config</structname></title>
|
|
|
|
<indexterm zone="catalog-pg-ts-config">
|
|
<primary>pg_ts_config</primary>
|
|
</indexterm>
|
|
|
|
<para>
|
|
The <structname>pg_ts_config</structname> catalog contains entries
|
|
representing text search configurations. A configuration specifies
|
|
a particular text search parser and a list of dictionaries to use
|
|
for each of the parser's output token types. The parser is shown
|
|
in the <structname>pg_ts_config</structname> entry, but the
|
|
token-to-dictionary mapping is defined by subsidiary entries in <link
|
|
linkend="catalog-pg-ts-config-map"><structname>pg_ts_config_map</structname></link>.
|
|
</para>
|
|
|
|
<para>
|
|
<productname>PostgreSQL</productname>'s text search features are
|
|
described at length in <xref linkend="textsearch">.
|
|
</para>
|
|
|
|
<table>
|
|
<title><structname>pg_ts_config</> Columns</title>
|
|
|
|
<tgroup cols="4">
|
|
<thead>
|
|
<row>
|
|
<entry>Name</entry>
|
|
<entry>Type</entry>
|
|
<entry>References</entry>
|
|
<entry>Description</entry>
|
|
</row>
|
|
</thead>
|
|
|
|
<tbody>
|
|
<row>
|
|
<entry><structfield>cfgname</structfield></entry>
|
|
<entry><type>name</type></entry>
|
|
<entry></entry>
|
|
<entry>Text search configuration name</entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry><structfield>cfgnamespace</structfield></entry>
|
|
<entry><type>oid</type></entry>
|
|
<entry><literal><link linkend="catalog-pg-namespace"><structname>pg_namespace</structname></link>.oid</literal></entry>
|
|
<entry>
|
|
The OID of the namespace that contains this configuration
|
|
</entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry><structfield>cfgowner</structfield></entry>
|
|
<entry><type>oid</type></entry>
|
|
<entry><literal><link linkend="catalog-pg-authid"><structname>pg_authid</structname></link>.oid</literal></entry>
|
|
<entry>Owner of the configuration</entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry><structfield>cfgparser</structfield></entry>
|
|
<entry><type>oid</type></entry>
|
|
<entry><literal><link linkend="catalog-pg-ts-parser"><structname>pg_ts_parser</structname></link>.oid</literal></entry>
|
|
<entry>The OID of the text search parser for this configuration</entry>
|
|
</row>
|
|
</tbody>
|
|
</tgroup>
|
|
</table>
|
|
</sect1>
|
|
|
|
|
|
<sect1 id="catalog-pg-ts-config-map">
|
|
<title><structname>pg_ts_config_map</structname></title>
|
|
|
|
<indexterm zone="catalog-pg-ts-config-map">
|
|
<primary>pg_ts_config_map</primary>
|
|
</indexterm>
|
|
|
|
<para>
|
|
The <structname>pg_ts_config_map</structname> catalog contains entries
|
|
showing which text search dictionaries should be consulted, and in
|
|
what order, for each output token type of each text search configuration's
|
|
parser.
|
|
</para>
|
|
|
|
<para>
|
|
<productname>PostgreSQL</productname>'s text search features are
|
|
described at length in <xref linkend="textsearch">.
|
|
</para>
|
|
|
|
<table>
|
|
<title><structname>pg_ts_config_map</> Columns</title>
|
|
|
|
<tgroup cols="4">
|
|
<thead>
|
|
<row>
|
|
<entry>Name</entry>
|
|
<entry>Type</entry>
|
|
<entry>References</entry>
|
|
<entry>Description</entry>
|
|
</row>
|
|
</thead>
|
|
|
|
<tbody>
|
|
<row>
|
|
<entry><structfield>mapcfg</structfield></entry>
|
|
<entry><type>oid</type></entry>
|
|
<entry><literal><link linkend="catalog-pg-ts-config"><structname>pg_ts_config</structname></link>.oid</literal></entry>
|
|
<entry>The OID of the <structname>pg_ts_config</> entry owning this map entry</entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry><structfield>maptokentype</structfield></entry>
|
|
<entry><type>integer</type></entry>
|
|
<entry></entry>
|
|
<entry>A token type emitted by the configuration's parser</entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry><structfield>mapseqno</structfield></entry>
|
|
<entry><type>integer</type></entry>
|
|
<entry></entry>
|
|
<entry>Order in which to consult this entry (lower
|
|
<structfield>mapseqno</>s first)</entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry><structfield>mapdict</structfield></entry>
|
|
<entry><type>oid</type></entry>
|
|
<entry><literal><link linkend="catalog-pg-ts-dict"><structname>pg_ts_dict</structname></link>.oid</literal></entry>
|
|
<entry>The OID of the text search dictionary to consult</entry>
|
|
</row>
|
|
</tbody>
|
|
</tgroup>
|
|
</table>
|
|
</sect1>
|
|
|
|
|
|
<sect1 id="catalog-pg-ts-dict">
|
|
<title><structname>pg_ts_dict</structname></title>
|
|
|
|
<indexterm zone="catalog-pg-ts-dict">
|
|
<primary>pg_ts_dict</primary>
|
|
</indexterm>
|
|
|
|
<para>
|
|
The <structname>pg_ts_dict</structname> catalog contains entries
|
|
defining text search dictionaries. A dictionary depends on a text
|
|
search template, which specifies all the implementation functions
|
|
needed; the dictionary itself provides values for the user-settable
|
|
parameters supported by the template. This division of labor allows
|
|
dictionaries to be created by unprivileged users. The parameters
|
|
are specified by a text string <structfield>dictinitoption</>,
|
|
whose format and meaning vary depending on the template.
|
|
</para>
|
|
|
|
<para>
|
|
<productname>PostgreSQL</productname>'s text search features are
|
|
described at length in <xref linkend="textsearch">.
|
|
</para>
|
|
|
|
<table>
|
|
<title><structname>pg_ts_dict</> Columns</title>
|
|
|
|
<tgroup cols="4">
|
|
<thead>
|
|
<row>
|
|
<entry>Name</entry>
|
|
<entry>Type</entry>
|
|
<entry>References</entry>
|
|
<entry>Description</entry>
|
|
</row>
|
|
</thead>
|
|
|
|
<tbody>
|
|
<row>
|
|
<entry><structfield>dictname</structfield></entry>
|
|
<entry><type>name</type></entry>
|
|
<entry></entry>
|
|
<entry>Text search dictionary name</entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry><structfield>dictnamespace</structfield></entry>
|
|
<entry><type>oid</type></entry>
|
|
<entry><literal><link linkend="catalog-pg-namespace"><structname>pg_namespace</structname></link>.oid</literal></entry>
|
|
<entry>
|
|
The OID of the namespace that contains this dictionary
|
|
</entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry><structfield>dictowner</structfield></entry>
|
|
<entry><type>oid</type></entry>
|
|
<entry><literal><link linkend="catalog-pg-authid"><structname>pg_authid</structname></link>.oid</literal></entry>
|
|
<entry>Owner of the dictionary</entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry><structfield>dicttemplate</structfield></entry>
|
|
<entry><type>oid</type></entry>
|
|
<entry><literal><link linkend="catalog-pg-ts-template"><structname>pg_ts_template</structname></link>.oid</literal></entry>
|
|
<entry>The OID of the text search template for this dictionary</entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry><structfield>dictinitoption</structfield></entry>
|
|
<entry><type>text</type></entry>
|
|
<entry></entry>
|
|
<entry>Initialization option string for the template</entry>
|
|
</row>
|
|
</tbody>
|
|
</tgroup>
|
|
</table>
|
|
</sect1>
|
|
|
|
|
|
<sect1 id="catalog-pg-ts-parser">
|
|
<title><structname>pg_ts_parser</structname></title>
|
|
|
|
<indexterm zone="catalog-pg-ts-parser">
|
|
<primary>pg_ts_parser</primary>
|
|
</indexterm>
|
|
|
|
<para>
|
|
The <structname>pg_ts_parser</structname> catalog contains entries
|
|
defining text search parsers. A parser is responsible for splitting
|
|
input text into lexemes and assigning a token type to each lexeme.
|
|
Since a parser must be implemented by C-language-level functions,
|
|
creation of new parsers is restricted to database superusers.
|
|
</para>
|
|
|
|
<para>
|
|
<productname>PostgreSQL</productname>'s text search features are
|
|
described at length in <xref linkend="textsearch">.
|
|
</para>
|
|
|
|
<table>
|
|
<title><structname>pg_ts_parser</> Columns</title>
|
|
|
|
<tgroup cols="4">
|
|
<thead>
|
|
<row>
|
|
<entry>Name</entry>
|
|
<entry>Type</entry>
|
|
<entry>References</entry>
|
|
<entry>Description</entry>
|
|
</row>
|
|
</thead>
|
|
|
|
<tbody>
|
|
<row>
|
|
<entry><structfield>prsname</structfield></entry>
|
|
<entry><type>name</type></entry>
|
|
<entry></entry>
|
|
<entry>Text search parser name</entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry><structfield>prsnamespace</structfield></entry>
|
|
<entry><type>oid</type></entry>
|
|
<entry><literal><link linkend="catalog-pg-namespace"><structname>pg_namespace</structname></link>.oid</literal></entry>
|
|
<entry>
|
|
The OID of the namespace that contains this parser
|
|
</entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry><structfield>prsstart</structfield></entry>
|
|
<entry><type>regproc</type></entry>
|
|
<entry><literal><link linkend="catalog-pg-proc"><structname>pg_proc</structname></link>.oid</literal></entry>
|
|
<entry>OID of the parser's startup function</entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry><structfield>prstoken</structfield></entry>
|
|
<entry><type>regproc</type></entry>
|
|
<entry><literal><link linkend="catalog-pg-proc"><structname>pg_proc</structname></link>.oid</literal></entry>
|
|
<entry>OID of the parser's next-token function</entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry><structfield>prsend</structfield></entry>
|
|
<entry><type>regproc</type></entry>
|
|
<entry><literal><link linkend="catalog-pg-proc"><structname>pg_proc</structname></link>.oid</literal></entry>
|
|
<entry>OID of the parser's shutdown function</entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry><structfield>prsheadline</structfield></entry>
|
|
<entry><type>regproc</type></entry>
|
|
<entry><literal><link linkend="catalog-pg-proc"><structname>pg_proc</structname></link>.oid</literal></entry>
|
|
<entry>OID of the parser's headline function</entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry><structfield>prslextype</structfield></entry>
|
|
<entry><type>regproc</type></entry>
|
|
<entry><literal><link linkend="catalog-pg-proc"><structname>pg_proc</structname></link>.oid</literal></entry>
|
|
<entry>OID of the parser's lextype function</entry>
|
|
</row>
|
|
</tbody>
|
|
</tgroup>
|
|
</table>
|
|
</sect1>
|
|
|
|
|
|
<sect1 id="catalog-pg-ts-template">
|
|
<title><structname>pg_ts_template</structname></title>
|
|
|
|
<indexterm zone="catalog-pg-ts-template">
|
|
<primary>pg_ts_template</primary>
|
|
</indexterm>
|
|
|
|
<para>
|
|
The <structname>pg_ts_template</structname> catalog contains entries
|
|
defining text search templates. A template is the implementation
|
|
skeleton for a class of text search dictionaries.
|
|
Since a template must be implemented by C-language-level functions,
|
|
creation of new templates is restricted to database superusers.
|
|
</para>
|
|
|
|
<para>
|
|
<productname>PostgreSQL</productname>'s text search features are
|
|
described at length in <xref linkend="textsearch">.
|
|
</para>
|
|
|
|
<table>
|
|
<title><structname>pg_ts_template</> Columns</title>
|
|
|
|
<tgroup cols="4">
|
|
<thead>
|
|
<row>
|
|
<entry>Name</entry>
|
|
<entry>Type</entry>
|
|
<entry>References</entry>
|
|
<entry>Description</entry>
|
|
</row>
|
|
</thead>
|
|
|
|
<tbody>
|
|
<row>
|
|
<entry><structfield>tmplname</structfield></entry>
|
|
<entry><type>name</type></entry>
|
|
<entry></entry>
|
|
<entry>Text search template name</entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry><structfield>tmplnamespace</structfield></entry>
|
|
<entry><type>oid</type></entry>
|
|
<entry><literal><link linkend="catalog-pg-namespace"><structname>pg_namespace</structname></link>.oid</literal></entry>
|
|
<entry>
|
|
The OID of the namespace that contains this template
|
|
</entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry><structfield>tmplinit</structfield></entry>
|
|
<entry><type>regproc</type></entry>
|
|
<entry><literal><link linkend="catalog-pg-proc"><structname>pg_proc</structname></link>.oid</literal></entry>
|
|
<entry>OID of the template's initialization function</entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry><structfield>tmpllexize</structfield></entry>
|
|
<entry><type>regproc</type></entry>
|
|
<entry><literal><link linkend="catalog-pg-proc"><structname>pg_proc</structname></link>.oid</literal></entry>
|
|
<entry>OID of the template's lexize function</entry>
|
|
</row>
|
|
</tbody>
|
|
</tgroup>
|
|
</table>
|
|
</sect1>
|
|
|
|
|
|
<sect1 id="catalog-pg-type">
|
|
<title><structname>pg_type</structname></title>
|
|
|
|
<indexterm zone="catalog-pg-type">
|
|
<primary>pg_type</primary>
|
|
</indexterm>
|
|
|
|
<para>
|
|
The catalog <structname>pg_type</structname> stores information about data
|
|
types. Base types and enum types (scalar types) are created with
|
|
<xref linkend="sql-createtype" endterm="sql-createtype-title">, and
|
|
domains with
|
|
<xref linkend="sql-createdomain" endterm="sql-createdomain-title">.
|
|
A composite type is automatically created for each table in the database, to
|
|
represent the row structure of the table. It is also possible to create
|
|
composite types with <command>CREATE TYPE AS</command>.
|
|
</para>
|
|
|
|
<table>
|
|
<title><structname>pg_type</> Columns</title>
|
|
|
|
<tgroup cols="4">
|
|
<thead>
|
|
<row>
|
|
<entry>Name</entry>
|
|
<entry>Type</entry>
|
|
<entry>References</entry>
|
|
<entry>Description</entry>
|
|
</row>
|
|
</thead>
|
|
|
|
<tbody>
|
|
<row>
|
|
<entry><structfield>typname</structfield></entry>
|
|
<entry><type>name</type></entry>
|
|
<entry></entry>
|
|
<entry>Data type name</entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry><structfield>typnamespace</structfield></entry>
|
|
<entry><type>oid</type></entry>
|
|
<entry><literal><link linkend="catalog-pg-namespace"><structname>pg_namespace</structname></link>.oid</literal></entry>
|
|
<entry>
|
|
The OID of the namespace that contains this type
|
|
</entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry><structfield>typowner</structfield></entry>
|
|
<entry><type>oid</type></entry>
|
|
<entry><literal><link linkend="catalog-pg-authid"><structname>pg_authid</structname></link>.oid</literal></entry>
|
|
<entry>Owner of the type</entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry><structfield>typlen</structfield></entry>
|
|
<entry><type>int2</type></entry>
|
|
<entry></entry>
|
|
<entry>
|
|
For a fixed-size type, <structfield>typlen</structfield> is the number
|
|
of bytes in the internal representation of the type. But for a
|
|
variable-length type, <structfield>typlen</structfield> is negative.
|
|
-1 indicates a <quote>varlena</> type (one that has a length word),
|
|
-2 indicates a null-terminated C string.
|
|
</entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry><structfield>typbyval</structfield></entry>
|
|
<entry><type>bool</type></entry>
|
|
<entry></entry>
|
|
<entry>
|
|
<structfield>typbyval</structfield> determines whether internal
|
|
routines pass a value of this type by value or by reference.
|
|
<structfield>typbyval</structfield> had better be false if
|
|
<structfield>typlen</structfield> is not 1, 2, or 4 (or 8 on machines
|
|
where Datum is 8 bytes).
|
|
Variable-length types are always passed by reference. Note that
|
|
<structfield>typbyval</structfield> can be false even if the
|
|
length would allow pass-by-value
|
|
</entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry><structfield>typtype</structfield></entry>
|
|
<entry><type>char</type></entry>
|
|
<entry></entry>
|
|
<entry>
|
|
<structfield>typtype</structfield> is
|
|
<literal>b</literal> for a base type,
|
|
<literal>c</literal> for a composite type (e.g., a table's row type),
|
|
<literal>d</literal> for a domain,
|
|
<literal>e</literal> for an enum type,
|
|
or <literal>p</literal> for a pseudo-type.
|
|
See also <structfield>typrelid</structfield> and
|
|
<structfield>typbasetype</structfield>
|
|
</entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry><structfield>typcategory</structfield></entry>
|
|
<entry><type>char</type></entry>
|
|
<entry></entry>
|
|
<entry>
|
|
<structfield>typcategory</structfield> is an arbitrary classification
|
|
of data types that is used by the parser to determine which implicit
|
|
casts should be <quote>preferred</>.
|
|
See <xref linkend="catalog-typcategory-table">
|
|
</entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry><structfield>typispreferred</structfield></entry>
|
|
<entry><type>bool</type></entry>
|
|
<entry></entry>
|
|
<entry>
|
|
True if the type is a preferred cast target within its
|
|
<structfield>typcategory</structfield>
|
|
</entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry><structfield>typisdefined</structfield></entry>
|
|
<entry><type>bool</type></entry>
|
|
<entry></entry>
|
|
<entry>
|
|
True if the type is defined, false if this is a placeholder
|
|
entry for a not-yet-defined type. When
|
|
<structfield>typisdefined</structfield> is false, nothing
|
|
except the type name, namespace, and OID can be relied on
|
|
</entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry><structfield>typdelim</structfield></entry>
|
|
<entry><type>char</type></entry>
|
|
<entry></entry>
|
|
<entry>
|
|
Character that separates two values of this type when parsing
|
|
array input. Note that the delimiter is associated with the array
|
|
element data type, not the array data type
|
|
</entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry><structfield>typrelid</structfield></entry>
|
|
<entry><type>oid</type></entry>
|
|
<entry><literal><link linkend="catalog-pg-class"><structname>pg_class</structname></link>.oid</literal></entry>
|
|
<entry>
|
|
If this is a composite type (see
|
|
<structfield>typtype</structfield>), then this column points to
|
|
the <structname>pg_class</structname> entry that defines the
|
|
corresponding table. (For a free-standing composite type, the
|
|
<structname>pg_class</structname> entry doesn't really represent
|
|
a table, but it is needed anyway for the type's
|
|
<structname>pg_attribute</structname> entries to link to.)
|
|
Zero for non-composite types
|
|
</entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry><structfield>typelem</structfield></entry>
|
|
<entry><type>oid</type></entry>
|
|
<entry><literal><link linkend="catalog-pg-type"><structname>pg_type</structname></link>.oid</literal></entry>
|
|
<entry>
|
|
If <structfield>typelem</structfield> is not 0 then it
|
|
identifies another row in <structname>pg_type</structname>.
|
|
The current type can then be subscripted like an array yielding
|
|
values of type <structfield>typelem</structfield>. A
|
|
<quote>true</quote> array type is variable length
|
|
(<structfield>typlen</structfield> = -1),
|
|
but some fixed-length (<structfield>typlen</structfield> > 0) types
|
|
also have nonzero <structfield>typelem</structfield>, for example
|
|
<type>name</type> and <type>point</type>.
|
|
If a fixed-length type has a <structfield>typelem</structfield> then
|
|
its internal representation must be some number of values of the
|
|
<structfield>typelem</structfield> data type with no other data.
|
|
Variable-length array types have a header defined by the array
|
|
subroutines
|
|
</entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry><structfield>typarray</structfield></entry>
|
|
<entry><type>oid</type></entry>
|
|
<entry><literal><link linkend="catalog-pg-type"><structname>pg_type</structname></link>.oid</literal></entry>
|
|
<entry>
|
|
If <structfield>typarray</structfield> is not 0 then it
|
|
identifies another row in <structname>pg_type</structname>, which
|
|
is the <quote>true</quote> array type having this type as element
|
|
</entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry><structfield>typinput</structfield></entry>
|
|
<entry><type>regproc</type></entry>
|
|
<entry><literal><link linkend="catalog-pg-proc"><structname>pg_proc</structname></link>.oid</literal></entry>
|
|
<entry>Input conversion function (text format)</entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry><structfield>typoutput</structfield></entry>
|
|
<entry><type>regproc</type></entry>
|
|
<entry><literal><link linkend="catalog-pg-proc"><structname>pg_proc</structname></link>.oid</literal></entry>
|
|
<entry>Output conversion function (text format)</entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry><structfield>typreceive</structfield></entry>
|
|
<entry><type>regproc</type></entry>
|
|
<entry><literal><link linkend="catalog-pg-proc"><structname>pg_proc</structname></link>.oid</literal></entry>
|
|
<entry>Input conversion function (binary format), or 0 if none</entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry><structfield>typsend</structfield></entry>
|
|
<entry><type>regproc</type></entry>
|
|
<entry><literal><link linkend="catalog-pg-proc"><structname>pg_proc</structname></link>.oid</literal></entry>
|
|
<entry>Output conversion function (binary format), or 0 if none</entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry><structfield>typmodin</structfield></entry>
|
|
<entry><type>regproc</type></entry>
|
|
<entry><literal><link linkend="catalog-pg-proc"><structname>pg_proc</structname></link>.oid</literal></entry>
|
|
<entry>Type modifier input function, or 0 if type does not support modifiers</entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry><structfield>typmodout</structfield></entry>
|
|
<entry><type>regproc</type></entry>
|
|
<entry><literal><link linkend="catalog-pg-proc"><structname>pg_proc</structname></link>.oid</literal></entry>
|
|
<entry>Type modifier output function, or 0 to use the standard format</entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry><structfield>typanalyze</structfield></entry>
|
|
<entry><type>regproc</type></entry>
|
|
<entry><literal><link linkend="catalog-pg-proc"><structname>pg_proc</structname></link>.oid</literal></entry>
|
|
<entry>Custom ANALYZE function, or 0 to use the standard function</entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry><structfield>typalign</structfield></entry>
|
|
<entry><type>char</type></entry>
|
|
<entry></entry>
|
|
<entry><para>
|
|
|
|
<structfield>typalign</structfield> is the alignment required
|
|
when storing a value of this type. It applies to storage on
|
|
disk as well as most representations of the value inside
|
|
<productname>PostgreSQL</>.
|
|
When multiple values are stored consecutively, such
|
|
as in the representation of a complete row on disk, padding is
|
|
inserted before a datum of this type so that it begins on the
|
|
specified boundary. The alignment reference is the beginning
|
|
of the first datum in the sequence.
|
|
</para><para>
|
|
Possible values are:
|
|
<itemizedlist>
|
|
<listitem>
|
|
<para><literal>c</> = <type>char</type> alignment, i.e., no alignment needed.</para>
|
|
</listitem>
|
|
<listitem>
|
|
<para><literal>s</> = <type>short</type> alignment (2 bytes on most machines).</para>
|
|
</listitem>
|
|
<listitem>
|
|
<para><literal>i</> = <type>int</type> alignment (4 bytes on most machines).</para>
|
|
</listitem>
|
|
<listitem>
|
|
<para><literal>d</> = <type>double</type> alignment (8 bytes on many machines, but by no means all).</para>
|
|
</listitem>
|
|
</itemizedlist>
|
|
</para><note>
|
|
<para>
|
|
For types used in system tables, it is critical that the size
|
|
and alignment defined in <structname>pg_type</structname>
|
|
agree with the way that the compiler will lay out the column in
|
|
a structure representing a table row.
|
|
</para>
|
|
</note></entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry><structfield>typstorage</structfield></entry>
|
|
<entry><type>char</type></entry>
|
|
<entry></entry>
|
|
<entry><para>
|
|
<structfield>typstorage</structfield> tells for varlena
|
|
types (those with <structfield>typlen</structfield> = -1) if
|
|
the type is prepared for toasting and what the default strategy
|
|
for attributes of this type should be.
|
|
Possible values are
|
|
<itemizedlist>
|
|
<listitem>
|
|
<para><literal>p</>: Value must always be stored plain.</para>
|
|
</listitem>
|
|
<listitem>
|
|
<para>
|
|
<literal>e</>: Value can be stored in a <quote>secondary</quote>
|
|
relation (if relation has one, see
|
|
<literal>pg_class.reltoastrelid</literal>).
|
|
</para>
|
|
</listitem>
|
|
<listitem>
|
|
<para><literal>m</>: Value can be stored compressed inline.</para>
|
|
</listitem>
|
|
<listitem>
|
|
<para><literal>x</>: Value can be stored compressed inline or stored in <quote>secondary</quote> storage.</para>
|
|
</listitem>
|
|
</itemizedlist>
|
|
Note that <literal>m</> columns can also be moved out to secondary
|
|
storage, but only as a last resort (<literal>e</> and <literal>x</> columns are
|
|
moved first).
|
|
</para></entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry><structfield>typnotnull</structfield></entry>
|
|
<entry><type>bool</type></entry>
|
|
<entry></entry>
|
|
<entry><para>
|
|
<structfield>typnotnull</structfield> represents a not-null
|
|
constraint on a type. Used for domains only
|
|
</para></entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry><structfield>typbasetype</structfield></entry>
|
|
<entry><type>oid</type></entry>
|
|
<entry><literal><link linkend="catalog-pg-type"><structname>pg_type</structname></link>.oid</literal></entry>
|
|
<entry><para>
|
|
If this is a domain (see <structfield>typtype</structfield>), then
|
|
<structfield>typbasetype</structfield> identifies the type that this
|
|
one is based on. Zero if this type is not a domain
|
|
</para></entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry><structfield>typtypmod</structfield></entry>
|
|
<entry><type>int4</type></entry>
|
|
<entry></entry>
|
|
<entry><para>
|
|
Domains use <structfield>typtypmod</structfield> to record the <literal>typmod</>
|
|
to be applied to their base type (-1 if base type does not use a
|
|
<literal>typmod</>). -1 if this type is not a domain
|
|
</para></entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry><structfield>typndims</structfield></entry>
|
|
<entry><type>int4</type></entry>
|
|
<entry></entry>
|
|
<entry><para>
|
|
<structfield>typndims</structfield> is the number of array dimensions
|
|
for a domain that is an array (that is, <structfield>typbasetype</> is
|
|
an array type; the domain's <structfield>typelem</> will match the base
|
|
type's <structfield>typelem</structfield>).
|
|
Zero for types other than domains over array types
|
|
</para></entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry><structfield>typdefaultbin</structfield></entry>
|
|
<entry><type>text</type></entry>
|
|
<entry></entry>
|
|
<entry><para>
|
|
If <structfield>typdefaultbin</> is not null, it is the <function>nodeToString()</function>
|
|
representation of a default expression for the type. This is
|
|
only used for domains
|
|
</para></entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry><structfield>typdefault</structfield></entry>
|
|
<entry><type>text</type></entry>
|
|
<entry></entry>
|
|
<entry><para>
|
|
<structfield>typdefault</> is null if the type has no associated
|
|
default value. If <structfield>typdefaultbin</> is not null,
|
|
<structfield>typdefault</> must contain a human-readable version of the
|
|
default expression represented by <structfield>typdefaultbin</>. If
|
|
<structfield>typdefaultbin</> is null and <structfield>typdefault</> is
|
|
not, then <structfield>typdefault</> is the external representation of
|
|
the type's default value, which might be fed to the type's input
|
|
converter to produce a constant
|
|
</para></entry>
|
|
</row>
|
|
</tbody>
|
|
</tgroup>
|
|
</table>
|
|
|
|
<para>
|
|
<xref linkend="catalog-typcategory-table"> lists the system-defined values
|
|
of <structfield>typcategory</>. Any future additions to this list will
|
|
also be upper-case ASCII letters. All other ASCII characters are reserved
|
|
for user-defined categories.
|
|
</para>
|
|
|
|
<table id="catalog-typcategory-table">
|
|
<title><structfield>typcategory</> Codes</title>
|
|
|
|
<tgroup cols="2">
|
|
<thead>
|
|
<row>
|
|
<entry>Code</entry>
|
|
<entry>Category</entry>
|
|
</row>
|
|
</thead>
|
|
|
|
<tbody>
|
|
<row>
|
|
<entry><literal>A</literal></entry>
|
|
<entry>Array types</entry>
|
|
</row>
|
|
<row>
|
|
<entry><literal>B</literal></entry>
|
|
<entry>Boolean types</entry>
|
|
</row>
|
|
<row>
|
|
<entry><literal>C</literal></entry>
|
|
<entry>Composite types</entry>
|
|
</row>
|
|
<row>
|
|
<entry><literal>D</literal></entry>
|
|
<entry>Date/time types</entry>
|
|
</row>
|
|
<row>
|
|
<entry><literal>E</literal></entry>
|
|
<entry>Enum types</entry>
|
|
</row>
|
|
<row>
|
|
<entry><literal>G</literal></entry>
|
|
<entry>Geometric types</entry>
|
|
</row>
|
|
<row>
|
|
<entry><literal>I</literal></entry>
|
|
<entry>Network address types</entry>
|
|
</row>
|
|
<row>
|
|
<entry><literal>N</literal></entry>
|
|
<entry>Numeric types</entry>
|
|
</row>
|
|
<row>
|
|
<entry><literal>P</literal></entry>
|
|
<entry>Pseudo-types</entry>
|
|
</row>
|
|
<row>
|
|
<entry><literal>S</literal></entry>
|
|
<entry>String types</entry>
|
|
</row>
|
|
<row>
|
|
<entry><literal>T</literal></entry>
|
|
<entry>Timespan types</entry>
|
|
</row>
|
|
<row>
|
|
<entry><literal>U</literal></entry>
|
|
<entry>User-defined types</entry>
|
|
</row>
|
|
<row>
|
|
<entry><literal>V</literal></entry>
|
|
<entry>Bit-string types</entry>
|
|
</row>
|
|
<row>
|
|
<entry><literal>X</literal></entry>
|
|
<entry><type>unknown</> type</entry>
|
|
</row>
|
|
</tbody>
|
|
</tgroup>
|
|
</table>
|
|
|
|
</sect1>
|
|
|
|
|
|
<sect1 id="catalog-pg-user-mapping">
|
|
<title><structname>pg_user_mapping</structname></title>
|
|
|
|
<indexterm zone="catalog-pg-user-mapping">
|
|
<primary>pg_user_mapping</primary>
|
|
</indexterm>
|
|
|
|
<para>
|
|
The catalog <structname>pg_user_mapping</structname> stores
|
|
the mappings from local user to remote. Access to this catalog is
|
|
restricted from normal users, use the view
|
|
<link linkend="view-pg-user-mappings"><structname>pg_user_mappings</structname></link>
|
|
instead.
|
|
</para>
|
|
|
|
<table>
|
|
<title><structname>pg_user_mapping</> Columns</title>
|
|
|
|
<tgroup cols="4">
|
|
<thead>
|
|
<row>
|
|
<entry>Name</entry>
|
|
<entry>Type</entry>
|
|
<entry>References</entry>
|
|
<entry>Description</entry>
|
|
</row>
|
|
</thead>
|
|
|
|
<tbody>
|
|
<row>
|
|
<entry><structfield>umuser</structfield></entry>
|
|
<entry><type>oid</type></entry>
|
|
<entry><literal><link linkend="catalog-pg-authid"><structname>pg_authid</structname></link>.oid</literal></entry>
|
|
<entry>OID of the local role being mapped, 0 if the user mapping is public</entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry><structfield>umserver</structfield></entry>
|
|
<entry><type>oid</type></entry>
|
|
<entry><literal><link linkend="catalog-pg-foreign-server"><structname>pg_foreign_server</structname></link>.oid</literal></entry>
|
|
<entry>
|
|
The OID of the foreign server that contains this mapping
|
|
</entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry><structfield>umoptions</structfield></entry>
|
|
<entry><type>text[]</type></entry>
|
|
<entry></entry>
|
|
<entry>
|
|
User mapping specific options, as <quote>keyword=value</> strings.
|
|
</entry>
|
|
</row>
|
|
</tbody>
|
|
</tgroup>
|
|
</table>
|
|
</sect1>
|
|
|
|
|
|
<sect1 id="views-overview">
|
|
<title>System Views</title>
|
|
|
|
<para>
|
|
In addition to the system catalogs, <productname>PostgreSQL</productname>
|
|
provides a number of built-in views. Some system views provide convenient
|
|
access to some commonly used queries on the system catalogs. Other views
|
|
provide access to internal server state.
|
|
</para>
|
|
|
|
<para>
|
|
The information schema (<xref linkend="information-schema">) provides
|
|
an alternative set of views which overlap the functionality of the system
|
|
views. Since the information schema is SQL-standard whereas the views
|
|
described here are <productname>PostgreSQL</productname>-specific,
|
|
it's usually better to use the information schema if it provides all
|
|
the information you need.
|
|
</para>
|
|
|
|
<para>
|
|
<xref linkend="view-table"> lists the system views described here.
|
|
More detailed documentation of each view follows below.
|
|
There are some additional views that provide access to the results of
|
|
the statistics collector; they are described in <xref
|
|
linkend="monitoring-stats-views-table">.
|
|
</para>
|
|
|
|
<para>
|
|
Except where noted, all the views described here are read-only.
|
|
</para>
|
|
|
|
<table id="view-table">
|
|
<title>System Views</title>
|
|
|
|
<tgroup cols="2">
|
|
<thead>
|
|
<row>
|
|
<entry>View Name</entry>
|
|
<entry>Purpose</entry>
|
|
</row>
|
|
</thead>
|
|
|
|
<tbody>
|
|
<row>
|
|
<entry><link linkend="view-pg-cursors"><structname>pg_cursors</structname></link></entry>
|
|
<entry>open cursors</entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry><link linkend="view-pg-group"><structname>pg_group</structname></link></entry>
|
|
<entry>groups of database users</entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry><link linkend="view-pg-indexes"><structname>pg_indexes</structname></link></entry>
|
|
<entry>indexes</entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry><link linkend="view-pg-locks"><structname>pg_locks</structname></link></entry>
|
|
<entry>currently held locks</entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry><link linkend="view-pg-prepared-statements"><structname>pg_prepared_statements</structname></link></entry>
|
|
<entry>prepared statements</entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry><link linkend="view-pg-prepared-xacts"><structname>pg_prepared_xacts</structname></link></entry>
|
|
<entry>prepared transactions</entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry><link linkend="view-pg-roles"><structname>pg_roles</structname></link></entry>
|
|
<entry>database roles</entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry><link linkend="view-pg-rules"><structname>pg_rules</structname></link></entry>
|
|
<entry>rules</entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry><link linkend="view-pg-settings"><structname>pg_settings</structname></link></entry>
|
|
<entry>parameter settings</entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry><link linkend="view-pg-shadow"><structname>pg_shadow</structname></link></entry>
|
|
<entry>database users</entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry><link linkend="view-pg-stats"><structname>pg_stats</structname></link></entry>
|
|
<entry>planner statistics</entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry><link linkend="view-pg-tables"><structname>pg_tables</structname></link></entry>
|
|
<entry>tables</entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry><link linkend="view-pg-timezone-abbrevs"><structname>pg_timezone_abbrevs</structname></link></entry>
|
|
<entry>time zone abbreviations</entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry><link linkend="view-pg-timezone-names"><structname>pg_timezone_names</structname></link></entry>
|
|
<entry>time zone names</entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry><link linkend="view-pg-user"><structname>pg_user</structname></link></entry>
|
|
<entry>database users</entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry><link linkend="view-pg-views"><structname>pg_views</structname></link></entry>
|
|
<entry>views</entry>
|
|
</row>
|
|
|
|
</tbody>
|
|
</tgroup>
|
|
</table>
|
|
</sect1>
|
|
|
|
<sect1 id="view-pg-cursors">
|
|
<title><structname>pg_cursors</structname></title>
|
|
|
|
<indexterm zone="view-pg-cursors">
|
|
<primary>pg_cursors</primary>
|
|
</indexterm>
|
|
|
|
<para>
|
|
The <structname>pg_cursors</structname> view lists the cursors that
|
|
are currently available. Cursors can be defined in several ways:
|
|
<itemizedlist>
|
|
<listitem>
|
|
<para>
|
|
via the <xref linkend="sql-declare" endterm="sql-declare-title">
|
|
statement in SQL
|
|
</para>
|
|
</listitem>
|
|
|
|
<listitem>
|
|
<para>
|
|
via the Bind message in the frontend/backend protocol, as
|
|
described in <xref linkend="protocol-flow-ext-query">
|
|
</para>
|
|
</listitem>
|
|
|
|
<listitem>
|
|
<para>
|
|
via the Server Programming Interface (SPI), as described in
|
|
<xref linkend="spi-interface">
|
|
</para>
|
|
</listitem>
|
|
</itemizedlist>
|
|
|
|
The <structname>pg_cursors</structname> view displays cursors
|
|
created by any of these means. Cursors only exist for the duration
|
|
of the transaction that defines them, unless they have been
|
|
declared <literal>WITH HOLD</literal>. Therefore non-holdable
|
|
cursors are only present in the view until the end of their
|
|
creating transaction.
|
|
|
|
<note>
|
|
<para>
|
|
Cursors are used internally to implement some of the components
|
|
of <productname>PostgreSQL</>, such as procedural languages.
|
|
Therefore, the <structname>pg_cursors</> view might include cursors
|
|
that have not been explicitly created by the user.
|
|
</para>
|
|
</note>
|
|
</para>
|
|
|
|
<table>
|
|
<title><structname>pg_cursors</> Columns</title>
|
|
|
|
<tgroup cols="3">
|
|
<thead>
|
|
<row>
|
|
<entry>Name</entry>
|
|
<entry>Type</entry>
|
|
<entry>Description</entry>
|
|
</row>
|
|
</thead>
|
|
|
|
<tbody>
|
|
<row>
|
|
<entry><structfield>name</structfield></entry>
|
|
<entry><type>text</type></entry>
|
|
<entry>The name of the cursor</entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry><structfield>statement</structfield></entry>
|
|
<entry><type>text</type></entry>
|
|
<entry>The verbatim query string submitted to declare this cursor</entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry><structfield>is_holdable</structfield></entry>
|
|
<entry><type>boolean</type></entry>
|
|
<entry>
|
|
<literal>true</literal> if the cursor is holdable (that is, it
|
|
can be accessed after the transaction that declared the cursor
|
|
has committed); <literal>false</literal> otherwise
|
|
</entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry><structfield>is_binary</structfield></entry>
|
|
<entry><type>boolean</type></entry>
|
|
<entry>
|
|
<literal>true</literal> if the cursor was declared
|
|
<literal>BINARY</literal>; <literal>false</literal>
|
|
otherwise
|
|
</entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry><structfield>is_scrollable</structfield></entry>
|
|
<entry><type>boolean</type></entry>
|
|
<entry>
|
|
<literal>true</> if the cursor is scrollable (that is, it
|
|
allows rows to be retrieved in a nonsequential manner);
|
|
<literal>false</literal> otherwise
|
|
</entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry><structfield>creation_time</structfield></entry>
|
|
<entry><type>timestamptz</type></entry>
|
|
<entry>The time at which the cursor was declared</entry>
|
|
</row>
|
|
</tbody>
|
|
</tgroup>
|
|
</table>
|
|
|
|
<para>
|
|
The <structname>pg_cursors</structname> view is read only.
|
|
</para>
|
|
|
|
</sect1>
|
|
|
|
<sect1 id="view-pg-group">
|
|
<title><structname>pg_group</structname></title>
|
|
|
|
<indexterm zone="view-pg-group">
|
|
<primary>pg_group</primary>
|
|
</indexterm>
|
|
|
|
<para>
|
|
The view <structname>pg_group</structname> exists for backwards
|
|
compatibility: it emulates a catalog that existed in
|
|
<productname>PostgreSQL</productname> before version 8.1.
|
|
It shows the names and members of all roles that are marked as not
|
|
<structfield>rolcanlogin</>, which is an approximation to the set
|
|
of roles that are being used as groups.
|
|
</para>
|
|
|
|
<table>
|
|
<title><structname>pg_group</> Columns</title>
|
|
|
|
<tgroup cols="4">
|
|
<thead>
|
|
<row>
|
|
<entry>Name</entry>
|
|
<entry>Type</entry>
|
|
<entry>References</entry>
|
|
<entry>Description</entry>
|
|
</row>
|
|
</thead>
|
|
|
|
<tbody>
|
|
<row>
|
|
<entry><structfield>groname</structfield></entry>
|
|
<entry><type>name</type></entry>
|
|
<entry><literal><link linkend="catalog-pg-authid"><structname>pg_authid</structname></link>.rolname</literal></entry>
|
|
<entry>Name of the group</entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry><structfield>grosysid</structfield></entry>
|
|
<entry><type>oid</type></entry>
|
|
<entry><literal><link linkend="catalog-pg-authid"><structname>pg_authid</structname></link>.oid</literal></entry>
|
|
<entry>ID of this group</entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry><structfield>grolist</structfield></entry>
|
|
<entry><type>oid[]</type></entry>
|
|
<entry><literal><link linkend="catalog-pg-authid"><structname>pg_authid</structname></link>.oid</literal></entry>
|
|
<entry>An array containing the IDs of the roles in this group</entry>
|
|
</row>
|
|
</tbody>
|
|
</tgroup>
|
|
</table>
|
|
|
|
</sect1>
|
|
|
|
<sect1 id="view-pg-indexes">
|
|
<title><structname>pg_indexes</structname></title>
|
|
|
|
<indexterm zone="view-pg-indexes">
|
|
<primary>pg_indexes</primary>
|
|
</indexterm>
|
|
|
|
<para>
|
|
The view <structname>pg_indexes</structname> provides access to
|
|
useful information about each index in the database.
|
|
</para>
|
|
|
|
<table>
|
|
<title><structname>pg_indexes</> Columns</title>
|
|
|
|
<tgroup cols="4">
|
|
<thead>
|
|
<row>
|
|
<entry>Name</entry>
|
|
<entry>Type</entry>
|
|
<entry>References</entry>
|
|
<entry>Description</entry>
|
|
</row>
|
|
</thead>
|
|
<tbody>
|
|
<row>
|
|
<entry><structfield>schemaname</structfield></entry>
|
|
<entry><type>name</type></entry>
|
|
<entry><literal><link linkend="catalog-pg-namespace"><structname>pg_namespace</structname></link>.nspname</literal></entry>
|
|
<entry>Name of schema containing table and index</entry>
|
|
</row>
|
|
<row>
|
|
<entry><structfield>tablename</structfield></entry>
|
|
<entry><type>name</type></entry>
|
|
<entry><literal><link linkend="catalog-pg-class"><structname>pg_class</structname></link>.relname</literal></entry>
|
|
<entry>Name of table the index is for</entry>
|
|
</row>
|
|
<row>
|
|
<entry><structfield>indexname</structfield></entry>
|
|
<entry><type>name</type></entry>
|
|
<entry><literal><link linkend="catalog-pg-class"><structname>pg_class</structname></link>.relname</literal></entry>
|
|
<entry>Name of index</entry>
|
|
</row>
|
|
<row>
|
|
<entry><structfield>tablespace</structfield></entry>
|
|
<entry><type>name</type></entry>
|
|
<entry><literal><link linkend="catalog-pg-tablespace"><structname>pg_tablespace</structname></link>.spcname</literal></entry>
|
|
<entry>Name of tablespace containing index (NULL if default for database)</entry>
|
|
</row>
|
|
<row>
|
|
<entry><structfield>indexdef</structfield></entry>
|
|
<entry><type>text</type></entry>
|
|
<entry></entry>
|
|
<entry>Index definition (a reconstructed <command>CREATE INDEX</command>
|
|
command)</entry>
|
|
</row>
|
|
</tbody>
|
|
</tgroup>
|
|
</table>
|
|
|
|
</sect1>
|
|
|
|
<sect1 id="view-pg-locks">
|
|
<title><structname>pg_locks</structname></title>
|
|
|
|
<indexterm zone="view-pg-locks">
|
|
<primary>pg_locks</primary>
|
|
</indexterm>
|
|
|
|
<para>
|
|
The view <structname>pg_locks</structname> provides access to
|
|
information about the locks held by open transactions within the
|
|
database server. See <xref linkend="mvcc"> for more discussion
|
|
of locking.
|
|
</para>
|
|
|
|
<para>
|
|
<structname>pg_locks</structname> contains one row per active lockable
|
|
object, requested lock mode, and relevant transaction. Thus, the same
|
|
lockable object might
|
|
appear many times, if multiple transactions are holding or waiting
|
|
for locks on it. However, an object that currently has no locks on it
|
|
will not appear at all.
|
|
</para>
|
|
|
|
<para>
|
|
There are several distinct types of lockable objects:
|
|
whole relations (e.g., tables), individual pages of relations,
|
|
individual tuples of relations,
|
|
transaction IDs (both virtual and permanent IDs),
|
|
and general database objects (identified by class OID and object OID,
|
|
in the same way as in <structname>pg_description</structname> or
|
|
<structname>pg_depend</structname>). Also, the right to extend a
|
|
relation is represented as a separate lockable object.
|
|
</para>
|
|
|
|
<table>
|
|
<title><structname>pg_locks</> Columns</title>
|
|
|
|
<tgroup cols="4">
|
|
<thead>
|
|
<row>
|
|
<entry>Name</entry>
|
|
<entry>Type</entry>
|
|
<entry>References</entry>
|
|
<entry>Description</entry>
|
|
</row>
|
|
</thead>
|
|
<tbody>
|
|
<row>
|
|
<entry><structfield>locktype</structfield></entry>
|
|
<entry><type>text</type></entry>
|
|
<entry></entry>
|
|
<entry>
|
|
type of the lockable object:
|
|
<literal>relation</>,
|
|
<literal>extend</>,
|
|
<literal>page</>,
|
|
<literal>tuple</>,
|
|
<literal>transactionid</>,
|
|
<literal>virtualxid</>,
|
|
<literal>object</>,
|
|
<literal>userlock</>, or
|
|
<literal>advisory</>
|
|
</entry>
|
|
</row>
|
|
<row>
|
|
<entry><structfield>database</structfield></entry>
|
|
<entry><type>oid</type></entry>
|
|
<entry><literal><link linkend="catalog-pg-database"><structname>pg_database</structname></link>.oid</literal></entry>
|
|
<entry>
|
|
OID of the database in which the object exists, or
|
|
zero if the object is a shared object, or
|
|
NULL if the object is a transaction ID
|
|
</entry>
|
|
</row>
|
|
<row>
|
|
<entry><structfield>relation</structfield></entry>
|
|
<entry><type>oid</type></entry>
|
|
<entry><literal><link linkend="catalog-pg-class"><structname>pg_class</structname></link>.oid</literal></entry>
|
|
<entry>
|
|
OID of the relation, or NULL if the object is not
|
|
a relation or part of a relation
|
|
</entry>
|
|
</row>
|
|
<row>
|
|
<entry><structfield>page</structfield></entry>
|
|
<entry><type>integer</type></entry>
|
|
<entry></entry>
|
|
<entry>
|
|
Page number within the relation, or NULL if the object
|
|
is not a tuple or relation page
|
|
</entry>
|
|
</row>
|
|
<row>
|
|
<entry><structfield>tuple</structfield></entry>
|
|
<entry><type>smallint</type></entry>
|
|
<entry></entry>
|
|
<entry>
|
|
Tuple number within the page, or NULL if the object is not a tuple
|
|
</entry>
|
|
</row>
|
|
<row>
|
|
<entry><structfield>virtualxid</structfield></entry>
|
|
<entry><type>text</type></entry>
|
|
<entry></entry>
|
|
<entry>
|
|
Virtual ID of a transaction, or NULL if the object is not a
|
|
virtual transaction ID
|
|
</entry>
|
|
</row>
|
|
<row>
|
|
<entry><structfield>transactionid</structfield></entry>
|
|
<entry><type>xid</type></entry>
|
|
<entry></entry>
|
|
<entry>
|
|
ID of a transaction, or NULL if the object is not a transaction ID
|
|
</entry>
|
|
</row>
|
|
<row>
|
|
<entry><structfield>classid</structfield></entry>
|
|
<entry><type>oid</type></entry>
|
|
<entry><literal><link linkend="catalog-pg-class"><structname>pg_class</structname></link>.oid</literal></entry>
|
|
<entry>
|
|
OID of the system catalog containing the object, or NULL if the
|
|
object is not a general database object
|
|
</entry>
|
|
</row>
|
|
<row>
|
|
<entry><structfield>objid</structfield></entry>
|
|
<entry><type>oid</type></entry>
|
|
<entry>any OID column</entry>
|
|
<entry>
|
|
OID of the object within its system catalog, or NULL if the
|
|
object is not a general database object.
|
|
For advisory locks it is used to distinguish the two key
|
|
spaces (<literal>1</> for an int8 key, <literal>2</> for two
|
|
int4 keys).
|
|
</entry>
|
|
</row>
|
|
<row>
|
|
<entry><structfield>objsubid</structfield></entry>
|
|
<entry><type>smallint</type></entry>
|
|
<entry></entry>
|
|
<entry>
|
|
For a table column, this is the column number (the
|
|
<structfield>classid</> and <structfield>objid</> refer to the
|
|
table itself). For all other object types, this column is
|
|
zero. NULL if the object is not a general database object
|
|
</entry>
|
|
</row>
|
|
<row>
|
|
<entry><structfield>virtualtransaction</structfield></entry>
|
|
<entry><type>text</type></entry>
|
|
<entry></entry>
|
|
<entry>
|
|
Virtual ID of the transaction that is holding or awaiting this lock
|
|
</entry>
|
|
</row>
|
|
<row>
|
|
<entry><structfield>pid</structfield></entry>
|
|
<entry><type>integer</type></entry>
|
|
<entry></entry>
|
|
<entry>
|
|
Process ID of the server process holding or awaiting this
|
|
lock. NULL if the lock is held by a prepared transaction
|
|
</entry>
|
|
</row>
|
|
<row>
|
|
<entry><structfield>mode</structfield></entry>
|
|
<entry><type>text</type></entry>
|
|
<entry></entry>
|
|
<entry>Name of the lock mode held or desired by this process (see <xref
|
|
linkend="locking-tables">)</entry>
|
|
</row>
|
|
<row>
|
|
<entry><structfield>granted</structfield></entry>
|
|
<entry><type>boolean</type></entry>
|
|
<entry></entry>
|
|
<entry>True if lock is held, false if lock is awaited</entry>
|
|
</row>
|
|
</tbody>
|
|
</tgroup>
|
|
</table>
|
|
|
|
<para>
|
|
<structfield>granted</structfield> is true in a row representing a lock
|
|
held by the indicated transaction. False indicates that this transaction is
|
|
currently waiting to acquire this lock, which implies that some other
|
|
transaction is holding a conflicting lock mode on the same lockable object.
|
|
The waiting transaction will sleep until the other lock is released (or a
|
|
deadlock situation is detected). A single transaction can be waiting to
|
|
acquire at most one lock at a time.
|
|
</para>
|
|
|
|
<para>
|
|
Every transaction holds an exclusive lock on its virtual transaction ID for
|
|
its entire duration. If a permanent ID is assigned to the transaction
|
|
(which normally happens only if the transaction changes the state of the
|
|
database), it also holds an exclusive lock on its permanent transaction ID
|
|
until it ends. When one transaction finds it necessary to wait specifically
|
|
for another transaction, it does so by attempting to acquire share lock on
|
|
the other transaction ID (either virtual or permanent ID depending on the
|
|
situation). That will succeed only when the other transaction
|
|
terminates and releases its locks.
|
|
</para>
|
|
|
|
<para>
|
|
Although tuples are a lockable type of object,
|
|
information about row-level locks is stored on disk, not in memory,
|
|
and therefore row-level locks normally do not appear in this view.
|
|
If a transaction is waiting for a
|
|
row-level lock, it will usually appear in the view as waiting for the
|
|
permanent transaction ID of the current holder of that row lock.
|
|
</para>
|
|
|
|
<para>
|
|
Advisory locks can be acquired on keys consisting of either a single
|
|
<type>bigint</type> value or two integer values. A <type>bigint</type> key is displayed with its
|
|
high-order half in the <structfield>classid</> column, its low-order half
|
|
in the <structfield>objid</> column, and <structfield>objsubid</> equal
|
|
to 1. Integer keys are displayed with the first key in the
|
|
<structfield>classid</> column, the second key in the <structfield>objid</>
|
|
column, and <structfield>objsubid</> equal to 2. The actual meaning of
|
|
the keys is up to the user. Advisory locks are local to each database,
|
|
so the <structfield>database</> column is meaningful for an advisory lock.
|
|
</para>
|
|
|
|
<para>
|
|
When the <structname>pg_locks</structname> view is accessed, the
|
|
internal lock manager data structures are momentarily locked, and
|
|
a copy is made for the view to display. This ensures that the
|
|
view produces a consistent set of results, while not blocking
|
|
normal lock manager operations longer than necessary. Nonetheless
|
|
there could be some impact on database performance if this view is
|
|
frequently accessed.
|
|
</para>
|
|
|
|
<para>
|
|
<structname>pg_locks</structname> provides a global view of all locks
|
|
in the database cluster, not only those relevant to the current database.
|
|
Although its <structfield>relation</structfield> column can be joined
|
|
against <structname>pg_class</>.<structfield>oid</> to identify locked
|
|
relations, this will only work correctly for relations in the current
|
|
database (those for which the <structfield>database</structfield> column
|
|
is either the current database's OID or zero).
|
|
</para>
|
|
|
|
<para>
|
|
The <structfield>pid</structfield> column can be joined to the
|
|
<structfield>procpid</structfield> column of the
|
|
<structname>pg_stat_activity</structname> view to get more
|
|
information on the session holding or waiting to hold each lock.
|
|
Also, if you are using prepared transactions, the
|
|
<structfield>transaction</> column can be joined to the
|
|
<structfield>transaction</structfield> column of the
|
|
<structname>pg_prepared_xacts</structname> view to get more
|
|
information on prepared transactions that hold locks.
|
|
(A prepared transaction can never be waiting for a lock,
|
|
but it continues to hold the locks it acquired while running.)
|
|
</para>
|
|
|
|
</sect1>
|
|
|
|
<sect1 id="view-pg-prepared-statements">
|
|
<title><structname>pg_prepared_statements</structname></title>
|
|
|
|
<indexterm zone="view-pg-prepared-statements">
|
|
<primary>pg_prepared_statements</primary>
|
|
</indexterm>
|
|
|
|
<para>
|
|
The <structname>pg_prepared_statements</structname> view displays
|
|
all the prepared statements that are available in the current
|
|
session. See <xref linkend="sql-prepare"
|
|
endterm="sql-prepare-title"> for more information about prepared
|
|
statements.
|
|
</para>
|
|
|
|
<para>
|
|
<structname>pg_prepared_statements</structname> contains one row
|
|
for each prepared statement. Rows are added to the view when a new
|
|
prepared statement is created and removed when a prepared statement
|
|
is released (for example, via the <xref linkend="sql-deallocate"
|
|
endterm="sql-deallocate-title"> command).
|
|
</para>
|
|
|
|
<table>
|
|
<title><structname>pg_prepared_statements</> Columns</title>
|
|
|
|
<tgroup cols="3">
|
|
<thead>
|
|
<row>
|
|
<entry>Name</entry>
|
|
<entry>Type</entry>
|
|
<entry>Description</entry>
|
|
</row>
|
|
</thead>
|
|
<tbody>
|
|
<row>
|
|
<entry><structfield>name</structfield></entry>
|
|
<entry><type>text</type></entry>
|
|
<entry>
|
|
The identifier of the prepared statement
|
|
</entry>
|
|
</row>
|
|
<row>
|
|
<entry><structfield>statement</structfield></entry>
|
|
<entry><type>text</type></entry>
|
|
<entry>
|
|
The query string submitted by the client to create this
|
|
prepared statement. For prepared statements created via SQL,
|
|
this is the <command>PREPARE</command> statement submitted by
|
|
the client. For prepared statements created via the
|
|
frontend/backend protocol, this is the text of the prepared
|
|
statement itself
|
|
</entry>
|
|
</row>
|
|
<row>
|
|
<entry><structfield>prepare_time</structfield></entry>
|
|
<entry><type>timestamptz</type></entry>
|
|
<entry>
|
|
The time at which the prepared statement was created
|
|
</entry>
|
|
</row>
|
|
<row>
|
|
<entry><structfield>parameter_types</structfield></entry>
|
|
<entry><type>regtype[]</type></entry>
|
|
<entry>
|
|
The expected parameter types for the prepared statement in the
|
|
form of an array of <type>regtype</type>. The OID corresponding
|
|
to an element of this array can be obtained by casting the
|
|
<type>regtype</type> value to <type>oid</type>
|
|
</entry>
|
|
</row>
|
|
<row>
|
|
<entry><structfield>from_sql</structfield></entry>
|
|
<entry><type>boolean</type></entry>
|
|
<entry>
|
|
<literal>true</literal> if the prepared statement was created
|
|
via the <command>PREPARE</command> SQL statement;
|
|
<literal>false</literal> if the statement was prepared via the
|
|
frontend/backend protocol
|
|
</entry>
|
|
</row>
|
|
</tbody>
|
|
</tgroup>
|
|
</table>
|
|
|
|
<para>
|
|
The <structname>pg_prepared_statements</structname> view is read only.
|
|
</para>
|
|
</sect1>
|
|
|
|
<sect1 id="view-pg-prepared-xacts">
|
|
<title><structname>pg_prepared_xacts</structname></title>
|
|
|
|
<indexterm zone="view-pg-prepared-xacts">
|
|
<primary>pg_prepared_xacts</primary>
|
|
</indexterm>
|
|
|
|
<para>
|
|
The view <structname>pg_prepared_xacts</structname> displays
|
|
information about transactions that are currently prepared for two-phase
|
|
commit (see <xref linkend="sql-prepare-transaction"
|
|
endterm="sql-prepare-transaction-title"> for details).
|
|
</para>
|
|
|
|
<para>
|
|
<structname>pg_prepared_xacts</structname> contains one row per prepared
|
|
transaction. An entry is removed when the transaction is committed or
|
|
rolled back.
|
|
</para>
|
|
|
|
<table>
|
|
<title><structname>pg_prepared_xacts</> Columns</title>
|
|
|
|
<tgroup cols="4">
|
|
<thead>
|
|
<row>
|
|
<entry>Name</entry>
|
|
<entry>Type</entry>
|
|
<entry>References</entry>
|
|
<entry>Description</entry>
|
|
</row>
|
|
</thead>
|
|
<tbody>
|
|
<row>
|
|
<entry><structfield>transaction</structfield></entry>
|
|
<entry><type>xid</type></entry>
|
|
<entry></entry>
|
|
<entry>
|
|
Numeric transaction identifier of the prepared transaction
|
|
</entry>
|
|
</row>
|
|
<row>
|
|
<entry><structfield>gid</structfield></entry>
|
|
<entry><type>text</type></entry>
|
|
<entry></entry>
|
|
<entry>
|
|
Global transaction identifier that was assigned to the transaction
|
|
</entry>
|
|
</row>
|
|
<row>
|
|
<entry><structfield>prepared</structfield></entry>
|
|
<entry><type>timestamp with time zone</type></entry>
|
|
<entry></entry>
|
|
<entry>
|
|
Time at which the transaction was prepared for commit
|
|
</entry>
|
|
</row>
|
|
<row>
|
|
<entry><structfield>owner</structfield></entry>
|
|
<entry><type>name</type></entry>
|
|
<entry><literal><link linkend="catalog-pg-authid"><structname>pg_authid</structname></link>.rolname</literal></entry>
|
|
<entry>
|
|
Name of the user that executed the transaction
|
|
</entry>
|
|
</row>
|
|
<row>
|
|
<entry><structfield>database</structfield></entry>
|
|
<entry><type>name</type></entry>
|
|
<entry><literal><link linkend="catalog-pg-database"><structname>pg_database</structname></link>.datname</literal></entry>
|
|
<entry>
|
|
Name of the database in which the transaction was executed
|
|
</entry>
|
|
</row>
|
|
</tbody>
|
|
</tgroup>
|
|
</table>
|
|
|
|
<para>
|
|
When the <structname>pg_prepared_xacts</structname> view is accessed, the
|
|
internal transaction manager data structures are momentarily locked, and
|
|
a copy is made for the view to display. This ensures that the
|
|
view produces a consistent set of results, while not blocking
|
|
normal operations longer than necessary. Nonetheless
|
|
there could be some impact on database performance if this view is
|
|
frequently accessed.
|
|
</para>
|
|
|
|
</sect1>
|
|
|
|
<sect1 id="view-pg-roles">
|
|
<title><structname>pg_roles</structname></title>
|
|
|
|
<indexterm zone="view-pg-roles">
|
|
<primary>pg_roles</primary>
|
|
</indexterm>
|
|
|
|
<para>
|
|
The view <structname>pg_roles</structname> provides access to
|
|
information about database roles. This is simply a publicly
|
|
readable view of
|
|
<link linkend="catalog-pg-authid"><structname>pg_authid</structname></link>
|
|
that blanks out the password field.
|
|
</para>
|
|
|
|
<para>
|
|
This view explicitly exposes the OID column of the underlying table,
|
|
since that is needed to do joins to other catalogs.
|
|
</para>
|
|
|
|
<table>
|
|
<title><structname>pg_roles</> Columns</title>
|
|
|
|
<tgroup cols="4">
|
|
<thead>
|
|
<row>
|
|
<entry>Name</entry>
|
|
<entry>Type</entry>
|
|
<entry>References</entry>
|
|
<entry>Description</entry>
|
|
</row>
|
|
</thead>
|
|
|
|
<tbody>
|
|
<row>
|
|
<entry><structfield>rolname</structfield></entry>
|
|
<entry><type>name</type></entry>
|
|
<entry></entry>
|
|
<entry>Role name</entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry><structfield>rolsuper</structfield></entry>
|
|
<entry><type>bool</type></entry>
|
|
<entry></entry>
|
|
<entry>Role has superuser privileges</entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry><structfield>rolinherit</structfield></entry>
|
|
<entry><type>bool</type></entry>
|
|
<entry></entry>
|
|
<entry>Role automatically inherits privileges of roles it is a
|
|
member of</entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry><structfield>rolcreaterole</structfield></entry>
|
|
<entry><type>bool</type></entry>
|
|
<entry></entry>
|
|
<entry>Role can create more roles</entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry><structfield>rolcreatedb</structfield></entry>
|
|
<entry><type>bool</type></entry>
|
|
<entry></entry>
|
|
<entry>Role can create databases</entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry><structfield>rolcatupdate</structfield></entry>
|
|
<entry><type>bool</type></entry>
|
|
<entry></entry>
|
|
<entry>
|
|
Role can update system catalogs directly. (Even a superuser cannot do
|
|
this unless this column is true.)
|
|
</entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry><structfield>rolcanlogin</structfield></entry>
|
|
<entry><type>bool</type></entry>
|
|
<entry></entry>
|
|
<entry>
|
|
Role can log in. That is, this role can be given as the initial
|
|
session authorization identifier
|
|
</entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry><structfield>rolconnlimit</structfield></entry>
|
|
<entry><type>int4</type></entry>
|
|
<entry></entry>
|
|
<entry>
|
|
For roles that can log in, this sets maximum number of concurrent
|
|
connections this role can make. -1 means no limit
|
|
</entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry><structfield>rolpassword</structfield></entry>
|
|
<entry><type>text</type></entry>
|
|
<entry></entry>
|
|
<entry>Not the password (always reads as <literal>********</>)</entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry><structfield>rolvaliduntil</structfield></entry>
|
|
<entry><type>timestamptz</type></entry>
|
|
<entry></entry>
|
|
<entry>Password expiry time (only used for password authentication);
|
|
NULL if no expiration</entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry><structfield>oid</structfield></entry>
|
|
<entry><type>oid</type></entry>
|
|
<entry><literal><link linkend="catalog-pg-authid"><structname>pg_authid</structname></link>.oid</literal></entry>
|
|
<entry>ID of role</entry>
|
|
</row>
|
|
</tbody>
|
|
</tgroup>
|
|
</table>
|
|
|
|
</sect1>
|
|
|
|
<sect1 id="view-pg-rules">
|
|
<title><structname>pg_rules</structname></title>
|
|
|
|
<indexterm zone="view-pg-rules">
|
|
<primary>pg_rules</primary>
|
|
</indexterm>
|
|
|
|
<para>
|
|
The view <structname>pg_rules</structname> provides access to
|
|
useful information about query rewrite rules.
|
|
</para>
|
|
|
|
<table>
|
|
<title><structname>pg_rules</> Columns</title>
|
|
|
|
<tgroup cols="4">
|
|
<thead>
|
|
<row>
|
|
<entry>Name</entry>
|
|
<entry>Type</entry>
|
|
<entry>References</entry>
|
|
<entry>Description</entry>
|
|
</row>
|
|
</thead>
|
|
<tbody>
|
|
<row>
|
|
<entry><structfield>schemaname</structfield></entry>
|
|
<entry><type>name</type></entry>
|
|
<entry><literal><link linkend="catalog-pg-namespace"><structname>pg_namespace</structname></link>.nspname</literal></entry>
|
|
<entry>Name of schema containing table</entry>
|
|
</row>
|
|
<row>
|
|
<entry><structfield>tablename</structfield></entry>
|
|
<entry><type>name</type></entry>
|
|
<entry><literal><link linkend="catalog-pg-class"><structname>pg_class</structname></link>.relname</literal></entry>
|
|
<entry>Name of table the rule is for</entry>
|
|
</row>
|
|
<row>
|
|
<entry><structfield>rulename</structfield></entry>
|
|
<entry><type>name</type></entry>
|
|
<entry><literal><link linkend="catalog-pg-rewrite"><structname>pg_rewrite</structname></link>.rulename</literal></entry>
|
|
<entry>Name of rule</entry>
|
|
</row>
|
|
<row>
|
|
<entry><structfield>definition</structfield></entry>
|
|
<entry><type>text</type></entry>
|
|
<entry></entry>
|
|
<entry>Rule definition (a reconstructed creation command)</entry>
|
|
</row>
|
|
</tbody>
|
|
</tgroup>
|
|
</table>
|
|
|
|
<para>
|
|
The <structname>pg_rules</> view excludes the <literal>ON SELECT</> rules
|
|
of views; those can be seen in <structname>pg_views</>.
|
|
</para>
|
|
|
|
</sect1>
|
|
|
|
<sect1 id="view-pg-settings">
|
|
<title><structname>pg_settings</structname></title>
|
|
|
|
<indexterm zone="view-pg-settings">
|
|
<primary>pg_settings</primary>
|
|
</indexterm>
|
|
|
|
<para>
|
|
The view <structname>pg_settings</structname> provides access to
|
|
run-time parameters of the server. It is essentially an alternative
|
|
interface to the <xref linkend="sql-show" endterm="sql-show-title">
|
|
and <xref linkend="sql-set" endterm="sql-set-title"> commands.
|
|
It also provides access to some facts about each parameter that are
|
|
not directly available from <command>SHOW</>, such as minimum and
|
|
maximum values.
|
|
</para>
|
|
|
|
<table>
|
|
<title><structname>pg_settings</> Columns</title>
|
|
|
|
<tgroup cols="3">
|
|
<thead>
|
|
<row>
|
|
<entry>Name</entry>
|
|
<entry>Type</entry>
|
|
<entry>Description</entry>
|
|
</row>
|
|
</thead>
|
|
<tbody>
|
|
<row>
|
|
<entry><structfield>name</structfield></entry>
|
|
<entry><type>text</type></entry>
|
|
<entry>Run-time configuration parameter name</entry>
|
|
</row>
|
|
<row>
|
|
<entry><structfield>setting</structfield></entry>
|
|
<entry><type>text</type></entry>
|
|
<entry>Current value of the parameter</entry>
|
|
</row>
|
|
<row>
|
|
<entry><structfield>unit</structfield></entry>
|
|
<entry><type>text</type></entry>
|
|
<entry>Implicit unit of the parameter</entry>
|
|
</row>
|
|
<row>
|
|
<entry><structfield>category</structfield></entry>
|
|
<entry><type>text</type></entry>
|
|
<entry>Logical group of the parameter</entry>
|
|
</row>
|
|
<row>
|
|
<entry><structfield>short_desc</structfield></entry>
|
|
<entry><type>text</type></entry>
|
|
<entry>A brief description of the parameter</entry>
|
|
</row>
|
|
<row>
|
|
<entry><structfield>extra_desc</structfield></entry>
|
|
<entry><type>text</type></entry>
|
|
<entry>Additional, more detailed, description of the parameter</entry>
|
|
</row>
|
|
<row>
|
|
<entry><structfield>context</structfield></entry>
|
|
<entry><type>text</type></entry>
|
|
<entry>Context required to set the parameter's value</entry>
|
|
</row>
|
|
<row>
|
|
<entry><structfield>vartype</structfield></entry>
|
|
<entry><type>text</type></entry>
|
|
<entry>Parameter type (<literal>bool</>, <literal>enum</>,
|
|
<literal>integer</>, <literal>real</>, or <literal>string</>)
|
|
</entry>
|
|
</row>
|
|
<row>
|
|
<entry><structfield>source</structfield></entry>
|
|
<entry><type>text</type></entry>
|
|
<entry>Source of the current parameter value</entry>
|
|
</row>
|
|
<row>
|
|
<entry><structfield>min_val</structfield></entry>
|
|
<entry><type>text</type></entry>
|
|
<entry>Minimum allowed value of the parameter (NULL for non-numeric
|
|
values)</entry>
|
|
</row>
|
|
<row>
|
|
<entry><structfield>max_val</structfield></entry>
|
|
<entry><type>text</type></entry>
|
|
<entry>Maximum allowed value of the parameter (NULL for non-numeric
|
|
values)</entry>
|
|
</row>
|
|
<row>
|
|
<entry><structfield>enumvals</structfield></entry>
|
|
<entry><type>text[]</type></entry>
|
|
<entry>Allowed values of an enum parameter (NULL for non-enum
|
|
values)</entry>
|
|
</row>
|
|
<row>
|
|
<entry><structfield>boot_val</structfield></entry>
|
|
<entry><type>text</type></entry>
|
|
<entry>Parameter value assumed at server startup if the parameter is
|
|
not otherwise set</entry>
|
|
</row>
|
|
<row>
|
|
<entry><structfield>reset_val</structfield></entry>
|
|
<entry><type>text</type></entry>
|
|
<entry>Value that <command>RESET</command> would reset the parameter to
|
|
in the current session</entry>
|
|
</row>
|
|
<row>
|
|
<entry><structfield>sourcefile</structfield></entry>
|
|
<entry><type>text</type></entry>
|
|
<entry>Configuration file the current value was set in (NULL for
|
|
values set from sources other than configuration files, or when
|
|
examined by a non-superuser).
|
|
Helpful when using configuration include directives</entry>
|
|
</row>
|
|
<row>
|
|
<entry><structfield>sourceline</structfield></entry>
|
|
<entry><type>integer</type></entry>
|
|
<entry>Line number within the configuration file the current value was
|
|
set at (NULL for values set from sources other than configuration files,
|
|
or when examined by a non-superuser)
|
|
</entry>
|
|
</row>
|
|
</tbody>
|
|
</tgroup>
|
|
</table>
|
|
|
|
<para>
|
|
The <structname>pg_settings</structname> view cannot be inserted into or
|
|
deleted from, but it can be updated. An <command>UPDATE</command> applied
|
|
to a row of <structname>pg_settings</structname> is equivalent to executing
|
|
the <xref linkend="sql-set" endterm="sql-set-title"> command on that named
|
|
parameter. The change only affects the value used by the current
|
|
session. If an <command>UPDATE</command> is issued within a transaction
|
|
that is later aborted, the effects of the <command>UPDATE</command> command
|
|
disappear when the transaction is rolled back. Once the surrounding
|
|
transaction is committed, the effects will persist until the end of the
|
|
session, unless overridden by another <command>UPDATE</command> or
|
|
<command>SET</command>.
|
|
</para>
|
|
|
|
</sect1>
|
|
|
|
<sect1 id="view-pg-shadow">
|
|
<title><structname>pg_shadow</structname></title>
|
|
|
|
<indexterm zone="view-pg-shadow">
|
|
<primary>pg_shadow</primary>
|
|
</indexterm>
|
|
|
|
<para>
|
|
The view <structname>pg_shadow</structname> exists for backwards
|
|
compatibility: it emulates a catalog that existed in
|
|
<productname>PostgreSQL</productname> before version 8.1.
|
|
It shows properties of all roles that are marked as
|
|
<structfield>rolcanlogin</>.
|
|
</para>
|
|
|
|
<para>
|
|
The name stems from the fact that this table
|
|
should not be readable by the public since it contains passwords.
|
|
<link linkend="view-pg-user"><structname>pg_user</structname></link>
|
|
is a publicly readable view on
|
|
<structname>pg_shadow</structname> that blanks out the password field.
|
|
</para>
|
|
|
|
<table>
|
|
<title><structname>pg_shadow</> Columns</title>
|
|
|
|
<tgroup cols="4">
|
|
<thead>
|
|
<row>
|
|
<entry>Name</entry>
|
|
<entry>Type</entry>
|
|
<entry>References</entry>
|
|
<entry>Description</entry>
|
|
</row>
|
|
</thead>
|
|
|
|
<tbody>
|
|
<row>
|
|
<entry><structfield>usename</structfield></entry>
|
|
<entry><type>name</type></entry>
|
|
<entry><literal><link linkend="catalog-pg-authid"><structname>pg_authid</structname></link>.rolname</literal></entry>
|
|
<entry>User name</entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry><structfield>usesysid</structfield></entry>
|
|
<entry><type>oid</type></entry>
|
|
<entry><literal><link linkend="catalog-pg-authid"><structname>pg_authid</structname></link>.oid</literal></entry>
|
|
<entry>ID of this user</entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry><structfield>usecreatedb</structfield></entry>
|
|
<entry><type>bool</type></entry>
|
|
<entry></entry>
|
|
<entry>User can create databases</entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry><structfield>usesuper</structfield></entry>
|
|
<entry><type>bool</type></entry>
|
|
<entry></entry>
|
|
<entry>User is a superuser</entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry><structfield>usecatupd</structfield></entry>
|
|
<entry><type>bool</type></entry>
|
|
<entry></entry>
|
|
<entry>
|
|
User can update system catalogs. (Even a superuser cannot do
|
|
this unless this column is true.)
|
|
</entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry><structfield>passwd</structfield></entry>
|
|
<entry><type>text</type></entry>
|
|
<entry></entry>
|
|
<entry>Password (possibly encrypted)</entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry><structfield>valuntil</structfield></entry>
|
|
<entry><type>abstime</type></entry>
|
|
<entry></entry>
|
|
<entry>Password expiry time (only used for password authentication)</entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry><structfield>useconfig</structfield></entry>
|
|
<entry><type>text[]</type></entry>
|
|
<entry></entry>
|
|
<entry>Session defaults for run-time configuration variables</entry>
|
|
</row>
|
|
</tbody>
|
|
</tgroup>
|
|
</table>
|
|
|
|
</sect1>
|
|
|
|
<sect1 id="view-pg-stats">
|
|
<title><structname>pg_stats</structname></title>
|
|
|
|
<indexterm zone="view-pg-stats">
|
|
<primary>pg_stats</primary>
|
|
</indexterm>
|
|
|
|
<para>
|
|
The view <structname>pg_stats</structname> provides access to
|
|
the information stored in the <link
|
|
linkend="catalog-pg-statistic"><structname>pg_statistic</structname></link>
|
|
catalog. This view allows access only to rows of
|
|
<structname>pg_statistic</structname> that correspond to tables the
|
|
user has permission to read, and therefore it is safe to allow public
|
|
read access to this view.
|
|
</para>
|
|
|
|
<para>
|
|
<structname>pg_stats</structname> is also designed to present the
|
|
information in a more readable format than the underlying catalog
|
|
— at the cost that its schema must be extended whenever new slot types
|
|
are defined for <structname>pg_statistic</structname>.
|
|
</para>
|
|
|
|
<table>
|
|
<title><structname>pg_stats</> Columns</title>
|
|
|
|
<tgroup cols="4">
|
|
<thead>
|
|
<row>
|
|
<entry>Name</entry>
|
|
<entry>Type</entry>
|
|
<entry>References</entry>
|
|
<entry>Description</entry>
|
|
</row>
|
|
</thead>
|
|
<tbody>
|
|
<row>
|
|
<entry><structfield>schemaname</structfield></entry>
|
|
<entry><type>name</type></entry>
|
|
<entry><literal><link linkend="catalog-pg-namespace"><structname>pg_namespace</structname></link>.nspname</literal></entry>
|
|
<entry>Name of schema containing table</entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry><structfield>tablename</structfield></entry>
|
|
<entry><type>name</type></entry>
|
|
<entry><literal><link linkend="catalog-pg-class"><structname>pg_class</structname></link>.relname</literal></entry>
|
|
<entry>Name of table</entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry><structfield>attname</structfield></entry>
|
|
<entry><type>name</type></entry>
|
|
<entry><literal><link linkend="catalog-pg-attribute"><structname>pg_attribute</structname></link>.attname</literal></entry>
|
|
<entry>Name of the column described by this row</entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry><structfield>inherited</structfield></entry>
|
|
<entry><type>bool</type></entry>
|
|
<entry></entry>
|
|
<entry>If true, this row includes inheritance child columns, not just the
|
|
values in the specified table</entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry><structfield>null_frac</structfield></entry>
|
|
<entry><type>real</type></entry>
|
|
<entry></entry>
|
|
<entry>Fraction of column entries that are null</entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry><structfield>avg_width</structfield></entry>
|
|
<entry><type>integer</type></entry>
|
|
<entry></entry>
|
|
<entry>Average width in bytes of column's entries</entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry><structfield>n_distinct</structfield></entry>
|
|
<entry><type>real</type></entry>
|
|
<entry></entry>
|
|
<entry>
|
|
If greater than zero, the estimated number of distinct values in the
|
|
column. If less than zero, the negative of the number of distinct
|
|
values divided by the number of rows. (The negated form is used when
|
|
<command>ANALYZE</> believes that the number of distinct values is
|
|
likely to increase as the table grows; the positive form is used when
|
|
the column seems to have a fixed number of possible values.) For
|
|
example, -1 indicates a unique column in which the number of distinct
|
|
values is the same as the number of rows
|
|
</entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry><structfield>most_common_vals</structfield></entry>
|
|
<entry><type>anyarray</type></entry>
|
|
<entry></entry>
|
|
<entry>
|
|
A list of the most common values in the column. (NULL if
|
|
no values seem to be more common than any others.)
|
|
For some datatypes such as <type>tsvector</>, this is a list of
|
|
the most common element values rather than values of the type itself.
|
|
</entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry><structfield>most_common_freqs</structfield></entry>
|
|
<entry><type>real[]</type></entry>
|
|
<entry></entry>
|
|
<entry>
|
|
A list of the frequencies of the most common values or elements,
|
|
i.e., number of occurrences of each divided by total number of rows.
|
|
(NULL when <structfield>most_common_vals</structfield> is.)
|
|
For some datatypes such as <type>tsvector</>, it can also store some
|
|
additional information, making it longer than the
|
|
<structfield>most_common_vals</> array.
|
|
</entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry><structfield>histogram_bounds</structfield></entry>
|
|
<entry><type>anyarray</type></entry>
|
|
<entry></entry>
|
|
<entry>
|
|
A list of values that divide the column's values into groups of
|
|
approximately equal population. The values in
|
|
<structfield>most_common_vals</>, if present, are omitted from this
|
|
histogram calculation. (This column is NULL if the column data type
|
|
does not have a <literal><</> operator or if the
|
|
<structfield>most_common_vals</> list accounts for the entire
|
|
population.)
|
|
</entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry><structfield>correlation</structfield></entry>
|
|
<entry><type>real</type></entry>
|
|
<entry></entry>
|
|
<entry>
|
|
Statistical correlation between physical row ordering and
|
|
logical ordering of the column values. This ranges from -1 to +1.
|
|
When the value is near -1 or +1, an index scan on the column will
|
|
be estimated to be cheaper than when it is near zero, due to reduction
|
|
of random access to the disk. (This column is NULL if the column data
|
|
type does not have a <literal><</> operator.)
|
|
</entry>
|
|
</row>
|
|
</tbody>
|
|
</tgroup>
|
|
</table>
|
|
|
|
<para>
|
|
The maximum number of entries in the <structfield>most_common_vals</>
|
|
and <structfield>histogram_bounds</> arrays can be set on a
|
|
column-by-column basis using the <command>ALTER TABLE SET STATISTICS</>
|
|
command, or globally by setting the
|
|
<xref linkend="guc-default-statistics-target"> run-time parameter.
|
|
</para>
|
|
|
|
</sect1>
|
|
|
|
<sect1 id="view-pg-tables">
|
|
<title><structname>pg_tables</structname></title>
|
|
|
|
<indexterm zone="view-pg-tables">
|
|
<primary>pg_tables</primary>
|
|
</indexterm>
|
|
|
|
<para>
|
|
The view <structname>pg_tables</structname> provides access to
|
|
useful information about each table in the database.
|
|
</para>
|
|
|
|
<table>
|
|
<title><structname>pg_tables</> Columns</title>
|
|
|
|
<tgroup cols="4">
|
|
<thead>
|
|
<row>
|
|
<entry>Name</entry>
|
|
<entry>Type</entry>
|
|
<entry>References</entry>
|
|
<entry>Description</entry>
|
|
</row>
|
|
</thead>
|
|
<tbody>
|
|
<row>
|
|
<entry><structfield>schemaname</structfield></entry>
|
|
<entry><type>name</type></entry>
|
|
<entry><literal><link linkend="catalog-pg-namespace"><structname>pg_namespace</structname></link>.nspname</literal></entry>
|
|
<entry>Name of schema containing table</entry>
|
|
</row>
|
|
<row>
|
|
<entry><structfield>tablename</structfield></entry>
|
|
<entry><type>name</type></entry>
|
|
<entry><literal><link linkend="catalog-pg-class"><structname>pg_class</structname></link>.relname</literal></entry>
|
|
<entry>Name of table</entry>
|
|
</row>
|
|
<row>
|
|
<entry><structfield>tableowner</structfield></entry>
|
|
<entry><type>name</type></entry>
|
|
<entry><literal><link linkend="catalog-pg-authid"><structname>pg_authid</structname></link>.rolname</literal></entry>
|
|
<entry>Name of table's owner</entry>
|
|
</row>
|
|
<row>
|
|
<entry><structfield>tablespace</structfield></entry>
|
|
<entry><type>name</type></entry>
|
|
<entry><literal><link linkend="catalog-pg-tablespace"><structname>pg_tablespace</structname></link>.spcname</literal></entry>
|
|
<entry>Name of tablespace containing table (NULL if default for database)</entry>
|
|
</row>
|
|
<row>
|
|
<entry><structfield>hasindexes</structfield></entry>
|
|
<entry><type>boolean</type></entry>
|
|
<entry><literal><link linkend="catalog-pg-class"><structname>pg_class</structname></link>.relhasindex</literal></entry>
|
|
<entry>true if table has (or recently had) any indexes</entry>
|
|
</row>
|
|
<row>
|
|
<entry><structfield>hasrules</structfield></entry>
|
|
<entry><type>boolean</type></entry>
|
|
<entry><literal><link linkend="catalog-pg-class"><structname>pg_class</structname></link>.relhasrules</literal></entry>
|
|
<entry>true if table has (or once had) rules</entry>
|
|
</row>
|
|
<row>
|
|
<entry><structfield>hastriggers</structfield></entry>
|
|
<entry><type>boolean</type></entry>
|
|
<entry><literal><link linkend="catalog-pg-class"><structname>pg_class</structname></link>.relhastriggers</literal></entry>
|
|
<entry>true if table has (or once had) triggers</entry>
|
|
</row>
|
|
</tbody>
|
|
</tgroup>
|
|
</table>
|
|
|
|
</sect1>
|
|
|
|
<sect1 id="view-pg-timezone-abbrevs">
|
|
<title><structname>pg_timezone_abbrevs</structname></title>
|
|
|
|
<indexterm zone="view-pg-timezone-abbrevs">
|
|
<primary>pg_timezone_abbrevs</primary>
|
|
</indexterm>
|
|
|
|
<para>
|
|
The view <structname>pg_timezone_abbrevs</structname> provides a list
|
|
of time zone abbreviations that are currently recognized by the datetime
|
|
input routines. The contents of this view change when the
|
|
<xref linkend="guc-timezone-abbreviations"> run-time parameter is modified.
|
|
</para>
|
|
|
|
<table>
|
|
<title><structname>pg_timezone_abbrevs</> Columns</title>
|
|
|
|
<tgroup cols="3">
|
|
<thead>
|
|
<row>
|
|
<entry>Name</entry>
|
|
<entry>Type</entry>
|
|
<entry>Description</entry>
|
|
</row>
|
|
</thead>
|
|
<tbody>
|
|
<row>
|
|
<entry><structfield>abbrev</structfield></entry>
|
|
<entry><type>text</type></entry>
|
|
<entry>Time zone abbreviation</entry>
|
|
</row>
|
|
<row>
|
|
<entry><structfield>utc_offset</structfield></entry>
|
|
<entry><type>interval</type></entry>
|
|
<entry>Offset from UTC (positive means east of Greenwich)</entry>
|
|
</row>
|
|
<row>
|
|
<entry><structfield>is_dst</structfield></entry>
|
|
<entry><type>boolean</type></entry>
|
|
<entry>True if this is a daylight-savings abbreviation</entry>
|
|
</row>
|
|
</tbody>
|
|
</tgroup>
|
|
</table>
|
|
|
|
</sect1>
|
|
|
|
<sect1 id="view-pg-timezone-names">
|
|
<title><structname>pg_timezone_names</structname></title>
|
|
|
|
<indexterm zone="view-pg-timezone-names">
|
|
<primary>pg_timezone_names</primary>
|
|
</indexterm>
|
|
|
|
<para>
|
|
The view <structname>pg_timezone_names</structname> provides a list
|
|
of time zone names that are recognized by <command>SET TIMEZONE</>,
|
|
along with their associated abbreviations, UTC offsets,
|
|
and daylight-savings status.
|
|
Unlike the abbreviations shown in <link
|
|
linkend="view-pg-timezone-abbrevs"><structname>pg_timezone_abbrevs</structname></link>, many of these names imply a set of daylight-savings transition
|
|
date rules. Therefore, the associated information changes across local DST
|
|
boundaries. The displayed information is computed based on the current
|
|
value of <function>CURRENT_TIMESTAMP</>.
|
|
</para>
|
|
|
|
<table>
|
|
<title><structname>pg_timezone_names</> Columns</title>
|
|
|
|
<tgroup cols="3">
|
|
<thead>
|
|
<row>
|
|
<entry>Name</entry>
|
|
<entry>Type</entry>
|
|
<entry>Description</entry>
|
|
</row>
|
|
</thead>
|
|
<tbody>
|
|
<row>
|
|
<entry><structfield>name</structfield></entry>
|
|
<entry><type>text</type></entry>
|
|
<entry>Time zone name</entry>
|
|
</row>
|
|
<row>
|
|
<entry><structfield>abbrev</structfield></entry>
|
|
<entry><type>text</type></entry>
|
|
<entry>Time zone abbreviation</entry>
|
|
</row>
|
|
<row>
|
|
<entry><structfield>utc_offset</structfield></entry>
|
|
<entry><type>interval</type></entry>
|
|
<entry>Offset from UTC (positive means east of Greenwich)</entry>
|
|
</row>
|
|
<row>
|
|
<entry><structfield>is_dst</structfield></entry>
|
|
<entry><type>boolean</type></entry>
|
|
<entry>True if currently observing daylight savings</entry>
|
|
</row>
|
|
</tbody>
|
|
</tgroup>
|
|
</table>
|
|
|
|
</sect1>
|
|
|
|
<sect1 id="view-pg-user">
|
|
<title><structname>pg_user</structname></title>
|
|
|
|
<indexterm zone="view-pg-user">
|
|
<primary>pg_user</primary>
|
|
</indexterm>
|
|
|
|
<para>
|
|
The view <structname>pg_user</structname> provides access to
|
|
information about database users. This is simply a publicly
|
|
readable view of
|
|
<link linkend="view-pg-shadow"><structname>pg_shadow</structname></link>
|
|
that blanks out the password field.
|
|
</para>
|
|
|
|
<table>
|
|
<title><structname>pg_user</> Columns</title>
|
|
|
|
<tgroup cols="3">
|
|
<thead>
|
|
<row>
|
|
<entry>Name</entry>
|
|
<entry>Type</entry>
|
|
<entry>Description</entry>
|
|
</row>
|
|
</thead>
|
|
<tbody>
|
|
<row>
|
|
<entry><structfield>usename</structfield></entry>
|
|
<entry><type>name</type></entry>
|
|
<entry>User name</entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry><structfield>usesysid</structfield></entry>
|
|
<entry><type>int4</type></entry>
|
|
<entry>User ID (arbitrary number used to reference this user)</entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry><structfield>usecreatedb</structfield></entry>
|
|
<entry><type>bool</type></entry>
|
|
<entry>User can create databases</entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry><structfield>usesuper</structfield></entry>
|
|
<entry><type>bool</type></entry>
|
|
<entry>User is a superuser</entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry><structfield>usecatupd</structfield></entry>
|
|
<entry><type>bool</type></entry>
|
|
<entry>
|
|
User can update system catalogs. (Even a superuser cannot do
|
|
this unless this column is true.)
|
|
</entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry><structfield>passwd</structfield></entry>
|
|
<entry><type>text</type></entry>
|
|
<entry>Not the password (always reads as <literal>********</>)</entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry><structfield>valuntil</structfield></entry>
|
|
<entry><type>abstime</type></entry>
|
|
<entry>Password expiry time (only used for password authentication)</entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry><structfield>useconfig</structfield></entry>
|
|
<entry><type>text[]</type></entry>
|
|
<entry>Session defaults for run-time configuration variables</entry>
|
|
</row>
|
|
</tbody>
|
|
</tgroup>
|
|
</table>
|
|
|
|
</sect1>
|
|
|
|
<sect1 id="view-pg-user-mappings">
|
|
<title><structname>pg_user_mappings</structname></title>
|
|
|
|
<indexterm zone="view-pg-user-mappings">
|
|
<primary>pg_user_mappings</primary>
|
|
</indexterm>
|
|
|
|
<para>
|
|
The view <structname>pg_user_mappings</structname> provides access
|
|
to information about user mappings. This is essentially a publicly
|
|
readable view of
|
|
<link linkend="catalog-pg-user-mapping"><structname>pg_user_mapping</structname></link>
|
|
that leaves out the options field if the user has no rights to use
|
|
it.
|
|
</para>
|
|
|
|
<table>
|
|
<title><structname>pg_user_mappings</> Columns</title>
|
|
|
|
<tgroup cols="4">
|
|
<thead>
|
|
<row>
|
|
<entry>Name</entry>
|
|
<entry>Type</entry>
|
|
<entry>References</entry>
|
|
<entry>Description</entry>
|
|
</row>
|
|
</thead>
|
|
|
|
<tbody>
|
|
<row>
|
|
<entry><structfield>umid</structfield></entry>
|
|
<entry><type>oid</type></entry>
|
|
<entry><literal><link linkend="catalog-pg-user-mapping"><structname>pg_user_mapping</structname></link>.oid</literal></entry>
|
|
<entry>OID of the user mapping</entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry><structfield>srvid</structfield></entry>
|
|
<entry><type>oid</type></entry>
|
|
<entry><literal><link linkend="catalog-pg-foreign-server"><structname>pg_foreign_server</structname></link>.oid</literal></entry>
|
|
<entry>
|
|
The OID of the foreign server that contains this mapping
|
|
</entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry><structfield>srvname</structfield></entry>
|
|
<entry><type>text</type></entry>
|
|
<entry></entry>
|
|
<entry>
|
|
Name of the foreign server
|
|
</entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry><structfield>umuser</structfield></entry>
|
|
<entry><type>oid</type></entry>
|
|
<entry><literal><link linkend="catalog-pg-authid"><structname>pg_authid</structname></link>.oid</literal></entry>
|
|
<entry>OID of the local role being mapped, 0 if the user mapping is public</entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry><structfield>usename</structfield></entry>
|
|
<entry><type>name</type></entry>
|
|
<entry></entry>
|
|
<entry>Name of the local user to be mapped</entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry><structfield>umoptions</structfield></entry>
|
|
<entry><type>text[]</type></entry>
|
|
<entry></entry>
|
|
<entry>
|
|
User mapping specific options, as <quote>keyword=value</>
|
|
strings, if the current user is the owner of the foreign
|
|
server, else null.
|
|
</entry>
|
|
</row>
|
|
</tbody>
|
|
</tgroup>
|
|
</table>
|
|
</sect1>
|
|
|
|
|
|
<sect1 id="view-pg-views">
|
|
<title><structname>pg_views</structname></title>
|
|
|
|
<indexterm zone="view-pg-views">
|
|
<primary>pg_views</primary>
|
|
</indexterm>
|
|
|
|
<para>
|
|
The view <structname>pg_views</structname> provides access to
|
|
useful information about each view in the database.
|
|
</para>
|
|
|
|
<table>
|
|
<title><structname>pg_views</> Columns</title>
|
|
|
|
<tgroup cols="4">
|
|
<thead>
|
|
<row>
|
|
<entry>Name</entry>
|
|
<entry>Type</entry>
|
|
<entry>References</entry>
|
|
<entry>Description</entry>
|
|
</row>
|
|
</thead>
|
|
<tbody>
|
|
<row>
|
|
<entry><structfield>schemaname</structfield></entry>
|
|
<entry><type>name</type></entry>
|
|
<entry><literal><link linkend="catalog-pg-namespace"><structname>pg_namespace</structname></link>.nspname</literal></entry>
|
|
<entry>Name of schema containing view</entry>
|
|
</row>
|
|
<row>
|
|
<entry><structfield>viewname</structfield></entry>
|
|
<entry><type>name</type></entry>
|
|
<entry><literal><link linkend="catalog-pg-class"><structname>pg_class</structname></link>.relname</literal></entry>
|
|
<entry>Name of view</entry>
|
|
</row>
|
|
<row>
|
|
<entry><structfield>viewowner</structfield></entry>
|
|
<entry><type>name</type></entry>
|
|
<entry><literal><link linkend="catalog-pg-authid"><structname>pg_authid</structname></link>.rolname</literal></entry>
|
|
<entry>Name of view's owner</entry>
|
|
</row>
|
|
<row>
|
|
<entry><structfield>definition</structfield></entry>
|
|
<entry><type>text</type></entry>
|
|
<entry></entry>
|
|
<entry>View definition (a reconstructed <command>SELECT</command> query)</entry>
|
|
</row>
|
|
</tbody>
|
|
</tgroup>
|
|
</table>
|
|
|
|
</sect1>
|
|
|
|
</chapter>
|