postgresql/src/include/catalog/pg_partitioned_table.h

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Implement table partitioning. Table partitioning is like table inheritance and reuses much of the existing infrastructure, but there are some important differences. The parent is called a partitioned table and is always empty; it may not have indexes or non-inherited constraints, since those make no sense for a relation with no data of its own. The children are called partitions and contain all of the actual data. Each partition has an implicit partitioning constraint. Multiple inheritance is not allowed, and partitioning and inheritance can't be mixed. Partitions can't have extra columns and may not allow nulls unless the parent does. Tuples inserted into the parent are automatically routed to the correct partition, so tuple-routing ON INSERT triggers are not needed. Tuple routing isn't yet supported for partitions which are foreign tables, and it doesn't handle updates that cross partition boundaries. Currently, tables can be range-partitioned or list-partitioned. List partitioning is limited to a single column, but range partitioning can involve multiple columns. A partitioning "column" can be an expression. Because table partitioning is less general than table inheritance, it is hoped that it will be easier to reason about properties of partitions, and therefore that this will serve as a better foundation for a variety of possible optimizations, including query planner optimizations. The tuple routing based which this patch does based on the implicit partitioning constraints is an example of this, but it seems likely that many other useful optimizations are also possible. Amit Langote, reviewed and tested by Robert Haas, Ashutosh Bapat, Amit Kapila, Rajkumar Raghuwanshi, Corey Huinker, Jaime Casanova, Rushabh Lathia, Erik Rijkers, among others. Minor revisions by me.
2016-12-07 19:17:43 +01:00
/*-------------------------------------------------------------------------
*
* pg_partitioned_table.h
* definition of the "partitioned table" system catalog
* (pg_partitioned_table)
Implement table partitioning. Table partitioning is like table inheritance and reuses much of the existing infrastructure, but there are some important differences. The parent is called a partitioned table and is always empty; it may not have indexes or non-inherited constraints, since those make no sense for a relation with no data of its own. The children are called partitions and contain all of the actual data. Each partition has an implicit partitioning constraint. Multiple inheritance is not allowed, and partitioning and inheritance can't be mixed. Partitions can't have extra columns and may not allow nulls unless the parent does. Tuples inserted into the parent are automatically routed to the correct partition, so tuple-routing ON INSERT triggers are not needed. Tuple routing isn't yet supported for partitions which are foreign tables, and it doesn't handle updates that cross partition boundaries. Currently, tables can be range-partitioned or list-partitioned. List partitioning is limited to a single column, but range partitioning can involve multiple columns. A partitioning "column" can be an expression. Because table partitioning is less general than table inheritance, it is hoped that it will be easier to reason about properties of partitions, and therefore that this will serve as a better foundation for a variety of possible optimizations, including query planner optimizations. The tuple routing based which this patch does based on the implicit partitioning constraints is an example of this, but it seems likely that many other useful optimizations are also possible. Amit Langote, reviewed and tested by Robert Haas, Ashutosh Bapat, Amit Kapila, Rajkumar Raghuwanshi, Corey Huinker, Jaime Casanova, Rushabh Lathia, Erik Rijkers, among others. Minor revisions by me.
2016-12-07 19:17:43 +01:00
*
*
* Portions Copyright (c) 1996-2024, PostgreSQL Global Development Group
* Portions Copyright (c) 1994, Regents of the University of California
Implement table partitioning. Table partitioning is like table inheritance and reuses much of the existing infrastructure, but there are some important differences. The parent is called a partitioned table and is always empty; it may not have indexes or non-inherited constraints, since those make no sense for a relation with no data of its own. The children are called partitions and contain all of the actual data. Each partition has an implicit partitioning constraint. Multiple inheritance is not allowed, and partitioning and inheritance can't be mixed. Partitions can't have extra columns and may not allow nulls unless the parent does. Tuples inserted into the parent are automatically routed to the correct partition, so tuple-routing ON INSERT triggers are not needed. Tuple routing isn't yet supported for partitions which are foreign tables, and it doesn't handle updates that cross partition boundaries. Currently, tables can be range-partitioned or list-partitioned. List partitioning is limited to a single column, but range partitioning can involve multiple columns. A partitioning "column" can be an expression. Because table partitioning is less general than table inheritance, it is hoped that it will be easier to reason about properties of partitions, and therefore that this will serve as a better foundation for a variety of possible optimizations, including query planner optimizations. The tuple routing based which this patch does based on the implicit partitioning constraints is an example of this, but it seems likely that many other useful optimizations are also possible. Amit Langote, reviewed and tested by Robert Haas, Ashutosh Bapat, Amit Kapila, Rajkumar Raghuwanshi, Corey Huinker, Jaime Casanova, Rushabh Lathia, Erik Rijkers, among others. Minor revisions by me.
2016-12-07 19:17:43 +01:00
*
* src/include/catalog/pg_partitioned_table.h
Implement table partitioning. Table partitioning is like table inheritance and reuses much of the existing infrastructure, but there are some important differences. The parent is called a partitioned table and is always empty; it may not have indexes or non-inherited constraints, since those make no sense for a relation with no data of its own. The children are called partitions and contain all of the actual data. Each partition has an implicit partitioning constraint. Multiple inheritance is not allowed, and partitioning and inheritance can't be mixed. Partitions can't have extra columns and may not allow nulls unless the parent does. Tuples inserted into the parent are automatically routed to the correct partition, so tuple-routing ON INSERT triggers are not needed. Tuple routing isn't yet supported for partitions which are foreign tables, and it doesn't handle updates that cross partition boundaries. Currently, tables can be range-partitioned or list-partitioned. List partitioning is limited to a single column, but range partitioning can involve multiple columns. A partitioning "column" can be an expression. Because table partitioning is less general than table inheritance, it is hoped that it will be easier to reason about properties of partitions, and therefore that this will serve as a better foundation for a variety of possible optimizations, including query planner optimizations. The tuple routing based which this patch does based on the implicit partitioning constraints is an example of this, but it seems likely that many other useful optimizations are also possible. Amit Langote, reviewed and tested by Robert Haas, Ashutosh Bapat, Amit Kapila, Rajkumar Raghuwanshi, Corey Huinker, Jaime Casanova, Rushabh Lathia, Erik Rijkers, among others. Minor revisions by me.
2016-12-07 19:17:43 +01:00
*
* NOTES
Replace our traditional initial-catalog-data format with a better design. Historically, the initial catalog data to be installed during bootstrap has been written in DATA() lines in the catalog header files. This had lots of disadvantages: the format was badly underdocumented, it was very difficult to edit the data in any mechanized way, and due to the lack of any abstraction the data was verbose, hard to read/understand, and easy to get wrong. Hence, move this data into separate ".dat" files and represent it in a way that can easily be read and rewritten by Perl scripts. The new format is essentially "key => value" for each column; while it's a bit repetitive, explicit labeling of each value makes the data far more readable and less error-prone. Provide a way to abbreviate entries by omitting field values that match a specified default value for their column. This allows removal of a large amount of repetitive boilerplate and also lowers the barrier to adding new columns. Also teach genbki.pl how to translate symbolic OID references into numeric OIDs for more cases than just "regproc"-like pg_proc references. It can now do that for regprocedure-like references (thus solving the problem that regproc is ambiguous for overloaded functions), operators, types, opfamilies, opclasses, and access methods. Use this to turn nearly all OID cross-references in the initial data into symbolic form. This represents a very large step forward in readability and error resistance of the initial catalog data. It should also reduce the difficulty of renumbering OID assignments in uncommitted patches. Also, solve the longstanding problem that frontend code that would like to use OID macros and other information from the catalog headers often had difficulty with backend-only code in the headers. To do this, arrange for all generated macros, plus such other declarations as we deem fit, to be placed in "derived" header files that are safe for frontend inclusion. (Once clients migrate to using these pg_*_d.h headers, it will be possible to get rid of the pg_*_fn.h headers, which only exist to quarantine code away from clients. That is left for follow-on patches, however.) The now-automatically-generated macros include the Anum_xxx and Natts_xxx constants that we used to have to update by hand when adding or removing catalog columns. Replace the former manual method of generating OID macros for pg_type entries with an automatic method, ensuring that all built-in types have OID macros. (But note that this patch does not change the way that OID macros for pg_proc entries are built and used. It's not clear that making that match the other catalogs would be worth extra code churn.) Add SGML documentation explaining what the new data format is and how to work with it. Despite being a very large change in the catalog headers, there is no catversion bump here, because postgres.bki and related output files haven't changed at all. John Naylor, based on ideas from various people; review and minor additional coding by me; previous review by Alvaro Herrera Discussion: https://postgr.es/m/CAJVSVGWO48JbbwXkJz_yBFyGYW-M9YWxnPdxJBUosDC9ou_F0Q@mail.gmail.com
2018-04-08 19:16:50 +02:00
* The Catalog.pm module reads this file and derives schema
* information.
Implement table partitioning. Table partitioning is like table inheritance and reuses much of the existing infrastructure, but there are some important differences. The parent is called a partitioned table and is always empty; it may not have indexes or non-inherited constraints, since those make no sense for a relation with no data of its own. The children are called partitions and contain all of the actual data. Each partition has an implicit partitioning constraint. Multiple inheritance is not allowed, and partitioning and inheritance can't be mixed. Partitions can't have extra columns and may not allow nulls unless the parent does. Tuples inserted into the parent are automatically routed to the correct partition, so tuple-routing ON INSERT triggers are not needed. Tuple routing isn't yet supported for partitions which are foreign tables, and it doesn't handle updates that cross partition boundaries. Currently, tables can be range-partitioned or list-partitioned. List partitioning is limited to a single column, but range partitioning can involve multiple columns. A partitioning "column" can be an expression. Because table partitioning is less general than table inheritance, it is hoped that it will be easier to reason about properties of partitions, and therefore that this will serve as a better foundation for a variety of possible optimizations, including query planner optimizations. The tuple routing based which this patch does based on the implicit partitioning constraints is an example of this, but it seems likely that many other useful optimizations are also possible. Amit Langote, reviewed and tested by Robert Haas, Ashutosh Bapat, Amit Kapila, Rajkumar Raghuwanshi, Corey Huinker, Jaime Casanova, Rushabh Lathia, Erik Rijkers, among others. Minor revisions by me.
2016-12-07 19:17:43 +01:00
*
*-------------------------------------------------------------------------
*/
#ifndef PG_PARTITIONED_TABLE_H
#define PG_PARTITIONED_TABLE_H
#include "catalog/genbki.h"
Replace our traditional initial-catalog-data format with a better design. Historically, the initial catalog data to be installed during bootstrap has been written in DATA() lines in the catalog header files. This had lots of disadvantages: the format was badly underdocumented, it was very difficult to edit the data in any mechanized way, and due to the lack of any abstraction the data was verbose, hard to read/understand, and easy to get wrong. Hence, move this data into separate ".dat" files and represent it in a way that can easily be read and rewritten by Perl scripts. The new format is essentially "key => value" for each column; while it's a bit repetitive, explicit labeling of each value makes the data far more readable and less error-prone. Provide a way to abbreviate entries by omitting field values that match a specified default value for their column. This allows removal of a large amount of repetitive boilerplate and also lowers the barrier to adding new columns. Also teach genbki.pl how to translate symbolic OID references into numeric OIDs for more cases than just "regproc"-like pg_proc references. It can now do that for regprocedure-like references (thus solving the problem that regproc is ambiguous for overloaded functions), operators, types, opfamilies, opclasses, and access methods. Use this to turn nearly all OID cross-references in the initial data into symbolic form. This represents a very large step forward in readability and error resistance of the initial catalog data. It should also reduce the difficulty of renumbering OID assignments in uncommitted patches. Also, solve the longstanding problem that frontend code that would like to use OID macros and other information from the catalog headers often had difficulty with backend-only code in the headers. To do this, arrange for all generated macros, plus such other declarations as we deem fit, to be placed in "derived" header files that are safe for frontend inclusion. (Once clients migrate to using these pg_*_d.h headers, it will be possible to get rid of the pg_*_fn.h headers, which only exist to quarantine code away from clients. That is left for follow-on patches, however.) The now-automatically-generated macros include the Anum_xxx and Natts_xxx constants that we used to have to update by hand when adding or removing catalog columns. Replace the former manual method of generating OID macros for pg_type entries with an automatic method, ensuring that all built-in types have OID macros. (But note that this patch does not change the way that OID macros for pg_proc entries are built and used. It's not clear that making that match the other catalogs would be worth extra code churn.) Add SGML documentation explaining what the new data format is and how to work with it. Despite being a very large change in the catalog headers, there is no catversion bump here, because postgres.bki and related output files haven't changed at all. John Naylor, based on ideas from various people; review and minor additional coding by me; previous review by Alvaro Herrera Discussion: https://postgr.es/m/CAJVSVGWO48JbbwXkJz_yBFyGYW-M9YWxnPdxJBUosDC9ou_F0Q@mail.gmail.com
2018-04-08 19:16:50 +02:00
#include "catalog/pg_partitioned_table_d.h"
Implement table partitioning. Table partitioning is like table inheritance and reuses much of the existing infrastructure, but there are some important differences. The parent is called a partitioned table and is always empty; it may not have indexes or non-inherited constraints, since those make no sense for a relation with no data of its own. The children are called partitions and contain all of the actual data. Each partition has an implicit partitioning constraint. Multiple inheritance is not allowed, and partitioning and inheritance can't be mixed. Partitions can't have extra columns and may not allow nulls unless the parent does. Tuples inserted into the parent are automatically routed to the correct partition, so tuple-routing ON INSERT triggers are not needed. Tuple routing isn't yet supported for partitions which are foreign tables, and it doesn't handle updates that cross partition boundaries. Currently, tables can be range-partitioned or list-partitioned. List partitioning is limited to a single column, but range partitioning can involve multiple columns. A partitioning "column" can be an expression. Because table partitioning is less general than table inheritance, it is hoped that it will be easier to reason about properties of partitions, and therefore that this will serve as a better foundation for a variety of possible optimizations, including query planner optimizations. The tuple routing based which this patch does based on the implicit partitioning constraints is an example of this, but it seems likely that many other useful optimizations are also possible. Amit Langote, reviewed and tested by Robert Haas, Ashutosh Bapat, Amit Kapila, Rajkumar Raghuwanshi, Corey Huinker, Jaime Casanova, Rushabh Lathia, Erik Rijkers, among others. Minor revisions by me.
2016-12-07 19:17:43 +01:00
/* ----------------
* pg_partitioned_table definition. cpp turns this into
* typedef struct FormData_pg_partitioned_table
* ----------------
*/
Remove WITH OIDS support, change oid catalog column visibility. Previously tables declared WITH OIDS, including a significant fraction of the catalog tables, stored the oid column not as a normal column, but as part of the tuple header. This special column was not shown by default, which was somewhat odd, as it's often (consider e.g. pg_class.oid) one of the more important parts of a row. Neither pg_dump nor COPY included the contents of the oid column by default. The fact that the oid column was not an ordinary column necessitated a significant amount of special case code to support oid columns. That already was painful for the existing, but upcoming work aiming to make table storage pluggable, would have required expanding and duplicating that "specialness" significantly. WITH OIDS has been deprecated since 2005 (commit ff02d0a05280e0). Remove it. Removing includes: - CREATE TABLE and ALTER TABLE syntax for declaring the table to be WITH OIDS has been removed (WITH (oids[ = true]) will error out) - pg_dump does not support dumping tables declared WITH OIDS and will issue a warning when dumping one (and ignore the oid column). - restoring an pg_dump archive with pg_restore will warn when restoring a table with oid contents (and ignore the oid column) - COPY will refuse to load binary dump that includes oids. - pg_upgrade will error out when encountering tables declared WITH OIDS, they have to be altered to remove the oid column first. - Functionality to access the oid of the last inserted row (like plpgsql's RESULT_OID, spi's SPI_lastoid, ...) has been removed. The syntax for declaring a table WITHOUT OIDS (or WITH (oids = false) for CREATE TABLE) is still supported. While that requires a bit of support code, it seems unnecessary to break applications / dumps that do not use oids, and are explicit about not using them. The biggest user of WITH OID columns was postgres' catalog. This commit changes all 'magic' oid columns to be columns that are normally declared and stored. To reduce unnecessary query breakage all the newly added columns are still named 'oid', even if a table's column naming scheme would indicate 'reloid' or such. This obviously requires adapting a lot code, mostly replacing oid access via HeapTupleGetOid() with access to the underlying Form_pg_*->oid column. The bootstrap process now assigns oids for all oid columns in genbki.pl that do not have an explicit value (starting at the largest oid previously used), only oids assigned later by oids will be above FirstBootstrapObjectId. As the oid column now is a normal column the special bootstrap syntax for oids has been removed. Oids are not automatically assigned during insertion anymore, all backend code explicitly assigns oids with GetNewOidWithIndex(). For the rare case that insertions into the catalog via SQL are called for the new pg_nextoid() function can be used (which only works on catalog tables). The fact that oid columns on system tables are now normal columns means that they will be included in the set of columns expanded by * (i.e. SELECT * FROM pg_class will now include the table's oid, previously it did not). It'd not technically be hard to hide oid column by default, but that'd mean confusing behavior would either have to be carried forward forever, or it'd cause breakage down the line. While it's not unlikely that further adjustments are needed, the scope/invasiveness of the patch makes it worthwhile to get merge this now. It's painful to maintain externally, too complicated to commit after the code code freeze, and a dependency of a number of other patches. Catversion bump, for obvious reasons. Author: Andres Freund, with contributions by John Naylor Discussion: https://postgr.es/m/20180930034810.ywp2c7awz7opzcfr@alap3.anarazel.de
2018-11-21 00:36:57 +01:00
CATALOG(pg_partitioned_table,3350,PartitionedRelationId)
Implement table partitioning. Table partitioning is like table inheritance and reuses much of the existing infrastructure, but there are some important differences. The parent is called a partitioned table and is always empty; it may not have indexes or non-inherited constraints, since those make no sense for a relation with no data of its own. The children are called partitions and contain all of the actual data. Each partition has an implicit partitioning constraint. Multiple inheritance is not allowed, and partitioning and inheritance can't be mixed. Partitions can't have extra columns and may not allow nulls unless the parent does. Tuples inserted into the parent are automatically routed to the correct partition, so tuple-routing ON INSERT triggers are not needed. Tuple routing isn't yet supported for partitions which are foreign tables, and it doesn't handle updates that cross partition boundaries. Currently, tables can be range-partitioned or list-partitioned. List partitioning is limited to a single column, but range partitioning can involve multiple columns. A partitioning "column" can be an expression. Because table partitioning is less general than table inheritance, it is hoped that it will be easier to reason about properties of partitions, and therefore that this will serve as a better foundation for a variety of possible optimizations, including query planner optimizations. The tuple routing based which this patch does based on the implicit partitioning constraints is an example of this, but it seems likely that many other useful optimizations are also possible. Amit Langote, reviewed and tested by Robert Haas, Ashutosh Bapat, Amit Kapila, Rajkumar Raghuwanshi, Corey Huinker, Jaime Casanova, Rushabh Lathia, Erik Rijkers, among others. Minor revisions by me.
2016-12-07 19:17:43 +01:00
{
Build in some knowledge about foreign-key relationships in the catalogs. This follows in the spirit of commit dfb75e478, which created primary key and uniqueness constraints to improve the visibility of constraints imposed on the system catalogs. While our catalogs contain many foreign-key-like relationships, they don't quite follow SQL semantics, in that the convention for an omitted reference is to write zero not NULL. Plus, we have some cases in which there are arrays each of whose elements is supposed to be an FK reference; SQL has no way to model that. So we can't create actual foreign key constraints to describe the situation. Nonetheless, we can collect and use knowledge about these relationships. This patch therefore adds annotations to the catalog header files to declare foreign-key relationships. (The BKI_LOOKUP annotations cover simple cases, but we weren't previously distinguishing which such columns are allowed to contain zeroes; we also need new markings for multi-column FK references.) Then, Catalog.pm and genbki.pl are taught to collect this information into a table in a new generated header "system_fk_info.h". The only user of that at the moment is a new SQL function pg_get_catalog_foreign_keys(), which exposes the table to SQL. The oidjoins regression test is rewritten to use pg_get_catalog_foreign_keys() to find out which columns to check. Aside from removing the need for manual maintenance of that test script, this allows it to cover numerous relationships that were not checked by the old implementation based on findoidjoins. (As of this commit, 217 relationships are checked by the test, versus 181 before.) Discussion: https://postgr.es/m/3240355.1612129197@sss.pgh.pa.us
2021-02-02 23:11:55 +01:00
Oid partrelid BKI_LOOKUP(pg_class); /* partitioned table oid */
char partstrat; /* partitioning strategy */
int16 partnatts; /* number of partition key columns */
Build in some knowledge about foreign-key relationships in the catalogs. This follows in the spirit of commit dfb75e478, which created primary key and uniqueness constraints to improve the visibility of constraints imposed on the system catalogs. While our catalogs contain many foreign-key-like relationships, they don't quite follow SQL semantics, in that the convention for an omitted reference is to write zero not NULL. Plus, we have some cases in which there are arrays each of whose elements is supposed to be an FK reference; SQL has no way to model that. So we can't create actual foreign key constraints to describe the situation. Nonetheless, we can collect and use knowledge about these relationships. This patch therefore adds annotations to the catalog header files to declare foreign-key relationships. (The BKI_LOOKUP annotations cover simple cases, but we weren't previously distinguishing which such columns are allowed to contain zeroes; we also need new markings for multi-column FK references.) Then, Catalog.pm and genbki.pl are taught to collect this information into a table in a new generated header "system_fk_info.h". The only user of that at the moment is a new SQL function pg_get_catalog_foreign_keys(), which exposes the table to SQL. The oidjoins regression test is rewritten to use pg_get_catalog_foreign_keys() to find out which columns to check. Aside from removing the need for manual maintenance of that test script, this allows it to cover numerous relationships that were not checked by the old implementation based on findoidjoins. (As of this commit, 217 relationships are checked by the test, versus 181 before.) Discussion: https://postgr.es/m/3240355.1612129197@sss.pgh.pa.us
2021-02-02 23:11:55 +01:00
Oid partdefid BKI_LOOKUP_OPT(pg_class); /* default partition oid;
* 0 if there isn't one */
Implement table partitioning. Table partitioning is like table inheritance and reuses much of the existing infrastructure, but there are some important differences. The parent is called a partitioned table and is always empty; it may not have indexes or non-inherited constraints, since those make no sense for a relation with no data of its own. The children are called partitions and contain all of the actual data. Each partition has an implicit partitioning constraint. Multiple inheritance is not allowed, and partitioning and inheritance can't be mixed. Partitions can't have extra columns and may not allow nulls unless the parent does. Tuples inserted into the parent are automatically routed to the correct partition, so tuple-routing ON INSERT triggers are not needed. Tuple routing isn't yet supported for partitions which are foreign tables, and it doesn't handle updates that cross partition boundaries. Currently, tables can be range-partitioned or list-partitioned. List partitioning is limited to a single column, but range partitioning can involve multiple columns. A partitioning "column" can be an expression. Because table partitioning is less general than table inheritance, it is hoped that it will be easier to reason about properties of partitions, and therefore that this will serve as a better foundation for a variety of possible optimizations, including query planner optimizations. The tuple routing based which this patch does based on the implicit partitioning constraints is an example of this, but it seems likely that many other useful optimizations are also possible. Amit Langote, reviewed and tested by Robert Haas, Ashutosh Bapat, Amit Kapila, Rajkumar Raghuwanshi, Corey Huinker, Jaime Casanova, Rushabh Lathia, Erik Rijkers, among others. Minor revisions by me.
2016-12-07 19:17:43 +01:00
/*
* variable-length fields start here, but we allow direct access to
* partattrs via the C struct. That's because the first variable-length
* field of a heap tuple can be reliably accessed using its C struct
* offset, as previous fields are all non-nullable fixed-length fields.
*/
int2vector partattrs BKI_FORCE_NOT_NULL; /* each member of the array is
* the attribute number of a
* partition key column, or 0
* if the column is actually
* an expression */
Implement table partitioning. Table partitioning is like table inheritance and reuses much of the existing infrastructure, but there are some important differences. The parent is called a partitioned table and is always empty; it may not have indexes or non-inherited constraints, since those make no sense for a relation with no data of its own. The children are called partitions and contain all of the actual data. Each partition has an implicit partitioning constraint. Multiple inheritance is not allowed, and partitioning and inheritance can't be mixed. Partitions can't have extra columns and may not allow nulls unless the parent does. Tuples inserted into the parent are automatically routed to the correct partition, so tuple-routing ON INSERT triggers are not needed. Tuple routing isn't yet supported for partitions which are foreign tables, and it doesn't handle updates that cross partition boundaries. Currently, tables can be range-partitioned or list-partitioned. List partitioning is limited to a single column, but range partitioning can involve multiple columns. A partitioning "column" can be an expression. Because table partitioning is less general than table inheritance, it is hoped that it will be easier to reason about properties of partitions, and therefore that this will serve as a better foundation for a variety of possible optimizations, including query planner optimizations. The tuple routing based which this patch does based on the implicit partitioning constraints is an example of this, but it seems likely that many other useful optimizations are also possible. Amit Langote, reviewed and tested by Robert Haas, Ashutosh Bapat, Amit Kapila, Rajkumar Raghuwanshi, Corey Huinker, Jaime Casanova, Rushabh Lathia, Erik Rijkers, among others. Minor revisions by me.
2016-12-07 19:17:43 +01:00
#ifdef CATALOG_VARLEN
Build in some knowledge about foreign-key relationships in the catalogs. This follows in the spirit of commit dfb75e478, which created primary key and uniqueness constraints to improve the visibility of constraints imposed on the system catalogs. While our catalogs contain many foreign-key-like relationships, they don't quite follow SQL semantics, in that the convention for an omitted reference is to write zero not NULL. Plus, we have some cases in which there are arrays each of whose elements is supposed to be an FK reference; SQL has no way to model that. So we can't create actual foreign key constraints to describe the situation. Nonetheless, we can collect and use knowledge about these relationships. This patch therefore adds annotations to the catalog header files to declare foreign-key relationships. (The BKI_LOOKUP annotations cover simple cases, but we weren't previously distinguishing which such columns are allowed to contain zeroes; we also need new markings for multi-column FK references.) Then, Catalog.pm and genbki.pl are taught to collect this information into a table in a new generated header "system_fk_info.h". The only user of that at the moment is a new SQL function pg_get_catalog_foreign_keys(), which exposes the table to SQL. The oidjoins regression test is rewritten to use pg_get_catalog_foreign_keys() to find out which columns to check. Aside from removing the need for manual maintenance of that test script, this allows it to cover numerous relationships that were not checked by the old implementation based on findoidjoins. (As of this commit, 217 relationships are checked by the test, versus 181 before.) Discussion: https://postgr.es/m/3240355.1612129197@sss.pgh.pa.us
2021-02-02 23:11:55 +01:00
oidvector partclass BKI_LOOKUP(pg_opclass) BKI_FORCE_NOT_NULL; /* operator class to
* compare keys */
oidvector partcollation BKI_LOOKUP_OPT(pg_collation) BKI_FORCE_NOT_NULL; /* user-specified
* collation for keys */
pg_node_tree partexprs; /* list of expressions in the partition key;
* one item for each zero entry in partattrs[] */
Implement table partitioning. Table partitioning is like table inheritance and reuses much of the existing infrastructure, but there are some important differences. The parent is called a partitioned table and is always empty; it may not have indexes or non-inherited constraints, since those make no sense for a relation with no data of its own. The children are called partitions and contain all of the actual data. Each partition has an implicit partitioning constraint. Multiple inheritance is not allowed, and partitioning and inheritance can't be mixed. Partitions can't have extra columns and may not allow nulls unless the parent does. Tuples inserted into the parent are automatically routed to the correct partition, so tuple-routing ON INSERT triggers are not needed. Tuple routing isn't yet supported for partitions which are foreign tables, and it doesn't handle updates that cross partition boundaries. Currently, tables can be range-partitioned or list-partitioned. List partitioning is limited to a single column, but range partitioning can involve multiple columns. A partitioning "column" can be an expression. Because table partitioning is less general than table inheritance, it is hoped that it will be easier to reason about properties of partitions, and therefore that this will serve as a better foundation for a variety of possible optimizations, including query planner optimizations. The tuple routing based which this patch does based on the implicit partitioning constraints is an example of this, but it seems likely that many other useful optimizations are also possible. Amit Langote, reviewed and tested by Robert Haas, Ashutosh Bapat, Amit Kapila, Rajkumar Raghuwanshi, Corey Huinker, Jaime Casanova, Rushabh Lathia, Erik Rijkers, among others. Minor revisions by me.
2016-12-07 19:17:43 +01:00
#endif
} FormData_pg_partitioned_table;
/* ----------------
* Form_pg_partitioned_table corresponds to a pointer to a tuple with
* the format of pg_partitioned_table relation.
Implement table partitioning. Table partitioning is like table inheritance and reuses much of the existing infrastructure, but there are some important differences. The parent is called a partitioned table and is always empty; it may not have indexes or non-inherited constraints, since those make no sense for a relation with no data of its own. The children are called partitions and contain all of the actual data. Each partition has an implicit partitioning constraint. Multiple inheritance is not allowed, and partitioning and inheritance can't be mixed. Partitions can't have extra columns and may not allow nulls unless the parent does. Tuples inserted into the parent are automatically routed to the correct partition, so tuple-routing ON INSERT triggers are not needed. Tuple routing isn't yet supported for partitions which are foreign tables, and it doesn't handle updates that cross partition boundaries. Currently, tables can be range-partitioned or list-partitioned. List partitioning is limited to a single column, but range partitioning can involve multiple columns. A partitioning "column" can be an expression. Because table partitioning is less general than table inheritance, it is hoped that it will be easier to reason about properties of partitions, and therefore that this will serve as a better foundation for a variety of possible optimizations, including query planner optimizations. The tuple routing based which this patch does based on the implicit partitioning constraints is an example of this, but it seems likely that many other useful optimizations are also possible. Amit Langote, reviewed and tested by Robert Haas, Ashutosh Bapat, Amit Kapila, Rajkumar Raghuwanshi, Corey Huinker, Jaime Casanova, Rushabh Lathia, Erik Rijkers, among others. Minor revisions by me.
2016-12-07 19:17:43 +01:00
* ----------------
*/
typedef FormData_pg_partitioned_table *Form_pg_partitioned_table;
DECLARE_TOAST(pg_partitioned_table, 4165, 4166);
DECLARE_UNIQUE_INDEX_PKEY(pg_partitioned_table_partrelid_index, 3351, PartitionedRelidIndexId, pg_partitioned_table, btree(partrelid oid_ops));
MAKE_SYSCACHE(PARTRELID, pg_partitioned_table_partrelid_index, 32);
Build in some knowledge about foreign-key relationships in the catalogs. This follows in the spirit of commit dfb75e478, which created primary key and uniqueness constraints to improve the visibility of constraints imposed on the system catalogs. While our catalogs contain many foreign-key-like relationships, they don't quite follow SQL semantics, in that the convention for an omitted reference is to write zero not NULL. Plus, we have some cases in which there are arrays each of whose elements is supposed to be an FK reference; SQL has no way to model that. So we can't create actual foreign key constraints to describe the situation. Nonetheless, we can collect and use knowledge about these relationships. This patch therefore adds annotations to the catalog header files to declare foreign-key relationships. (The BKI_LOOKUP annotations cover simple cases, but we weren't previously distinguishing which such columns are allowed to contain zeroes; we also need new markings for multi-column FK references.) Then, Catalog.pm and genbki.pl are taught to collect this information into a table in a new generated header "system_fk_info.h". The only user of that at the moment is a new SQL function pg_get_catalog_foreign_keys(), which exposes the table to SQL. The oidjoins regression test is rewritten to use pg_get_catalog_foreign_keys() to find out which columns to check. Aside from removing the need for manual maintenance of that test script, this allows it to cover numerous relationships that were not checked by the old implementation based on findoidjoins. (As of this commit, 217 relationships are checked by the test, versus 181 before.) Discussion: https://postgr.es/m/3240355.1612129197@sss.pgh.pa.us
2021-02-02 23:11:55 +01:00
/* partattrs can contain zero (InvalidAttrNumber) to represent expressions */
DECLARE_ARRAY_FOREIGN_KEY_OPT((partrelid, partattrs), pg_attribute, (attrelid, attnum));
Implement table partitioning. Table partitioning is like table inheritance and reuses much of the existing infrastructure, but there are some important differences. The parent is called a partitioned table and is always empty; it may not have indexes or non-inherited constraints, since those make no sense for a relation with no data of its own. The children are called partitions and contain all of the actual data. Each partition has an implicit partitioning constraint. Multiple inheritance is not allowed, and partitioning and inheritance can't be mixed. Partitions can't have extra columns and may not allow nulls unless the parent does. Tuples inserted into the parent are automatically routed to the correct partition, so tuple-routing ON INSERT triggers are not needed. Tuple routing isn't yet supported for partitions which are foreign tables, and it doesn't handle updates that cross partition boundaries. Currently, tables can be range-partitioned or list-partitioned. List partitioning is limited to a single column, but range partitioning can involve multiple columns. A partitioning "column" can be an expression. Because table partitioning is less general than table inheritance, it is hoped that it will be easier to reason about properties of partitions, and therefore that this will serve as a better foundation for a variety of possible optimizations, including query planner optimizations. The tuple routing based which this patch does based on the implicit partitioning constraints is an example of this, but it seems likely that many other useful optimizations are also possible. Amit Langote, reviewed and tested by Robert Haas, Ashutosh Bapat, Amit Kapila, Rajkumar Raghuwanshi, Corey Huinker, Jaime Casanova, Rushabh Lathia, Erik Rijkers, among others. Minor revisions by me.
2016-12-07 19:17:43 +01:00
#endif /* PG_PARTITIONED_TABLE_H */