212 lines
7.0 KiB
C
212 lines
7.0 KiB
C
/*-------------------------------------------------------------------------
|
|
*
|
|
* pg_attribute.h
|
|
* definition of the "attribute" system catalog (pg_attribute)
|
|
*
|
|
* The initial contents of pg_attribute are generated at compile time by
|
|
* genbki.pl, so there is no pg_attribute.dat file. Only "bootstrapped"
|
|
* relations need be included.
|
|
*
|
|
*
|
|
* Portions Copyright (c) 1996-2019, PostgreSQL Global Development Group
|
|
* Portions Copyright (c) 1994, Regents of the University of California
|
|
*
|
|
* src/include/catalog/pg_attribute.h
|
|
*
|
|
* NOTES
|
|
* The Catalog.pm module reads this file and derives schema
|
|
* information.
|
|
*
|
|
*-------------------------------------------------------------------------
|
|
*/
|
|
#ifndef PG_ATTRIBUTE_H
|
|
#define PG_ATTRIBUTE_H
|
|
|
|
#include "catalog/genbki.h"
|
|
#include "catalog/pg_attribute_d.h"
|
|
|
|
/* ----------------
|
|
* pg_attribute definition. cpp turns this into
|
|
* typedef struct FormData_pg_attribute
|
|
*
|
|
* If you change the following, make sure you change the structs for
|
|
* system attributes in catalog/heap.c also.
|
|
* You may need to change catalog/genbki.pl as well.
|
|
* ----------------
|
|
*/
|
|
CATALOG(pg_attribute,1249,AttributeRelationId) BKI_BOOTSTRAP BKI_ROWTYPE_OID(75,AttributeRelation_Rowtype_Id) BKI_SCHEMA_MACRO
|
|
{
|
|
Oid attrelid; /* OID of relation containing this attribute */
|
|
NameData attname; /* name of attribute */
|
|
|
|
/*
|
|
* atttypid is the OID of the instance in Catalog Class pg_type that
|
|
* defines the data type of this attribute (e.g. int4). Information in
|
|
* that instance is redundant with the attlen, attbyval, and attalign
|
|
* attributes of this instance, so they had better match or Postgres will
|
|
* fail.
|
|
*/
|
|
Oid atttypid;
|
|
|
|
/*
|
|
* attstattarget is the target number of statistics datapoints to collect
|
|
* during VACUUM ANALYZE of this column. A zero here indicates that we do
|
|
* not wish to collect any stats about this column. A "-1" here indicates
|
|
* that no value has been explicitly set for this column, so ANALYZE
|
|
* should use the default setting.
|
|
*/
|
|
int32 attstattarget BKI_DEFAULT(-1);
|
|
|
|
/*
|
|
* attlen is a copy of the typlen field from pg_type for this attribute.
|
|
* See atttypid comments above.
|
|
*/
|
|
int16 attlen;
|
|
|
|
/*
|
|
* attnum is the "attribute number" for the attribute: A value that
|
|
* uniquely identifies this attribute within its class. For user
|
|
* attributes, Attribute numbers are greater than 0 and not greater than
|
|
* the number of attributes in the class. I.e. if the Class pg_class says
|
|
* that Class XYZ has 10 attributes, then the user attribute numbers in
|
|
* Class pg_attribute must be 1-10.
|
|
*
|
|
* System attributes have attribute numbers less than 0 that are unique
|
|
* within the class, but not constrained to any particular range.
|
|
*
|
|
* Note that (attnum - 1) is often used as the index to an array.
|
|
*/
|
|
int16 attnum;
|
|
|
|
/*
|
|
* attndims is the declared number of dimensions, if an array type,
|
|
* otherwise zero.
|
|
*/
|
|
int32 attndims;
|
|
|
|
/*
|
|
* fastgetattr() uses attcacheoff to cache byte offsets of attributes in
|
|
* heap tuples. The value actually stored in pg_attribute (-1) indicates
|
|
* no cached value. But when we copy these tuples into a tuple
|
|
* descriptor, we may then update attcacheoff in the copies. This speeds
|
|
* up the attribute walking process.
|
|
*/
|
|
int32 attcacheoff BKI_DEFAULT(-1);
|
|
|
|
/*
|
|
* atttypmod records type-specific data supplied at table creation time
|
|
* (for example, the max length of a varchar field). It is passed to
|
|
* type-specific input and output functions as the third argument. The
|
|
* value will generally be -1 for types that do not need typmod.
|
|
*/
|
|
int32 atttypmod BKI_DEFAULT(-1);
|
|
|
|
/*
|
|
* attbyval is a copy of the typbyval field from pg_type for this
|
|
* attribute. See atttypid comments above.
|
|
*/
|
|
bool attbyval;
|
|
|
|
/*----------
|
|
* attstorage tells for VARLENA attributes, what the heap access
|
|
* methods can do to it if a given tuple doesn't fit into a page.
|
|
* Possible values are
|
|
* 'p': Value must be stored plain always
|
|
* 'e': Value can be stored in "secondary" relation (if relation
|
|
* has one, see pg_class.reltoastrelid)
|
|
* 'm': Value can be stored compressed inline
|
|
* 'x': Value can be stored compressed inline or in "secondary"
|
|
* Note that 'm' fields can also be moved out to secondary storage,
|
|
* but only as a last resort ('e' and 'x' fields are moved first).
|
|
*----------
|
|
*/
|
|
char attstorage;
|
|
|
|
/*
|
|
* attalign is a copy of the typalign field from pg_type for this
|
|
* attribute. See atttypid comments above.
|
|
*/
|
|
char attalign;
|
|
|
|
/* This flag represents the "NOT NULL" constraint */
|
|
bool attnotnull;
|
|
|
|
/* Has DEFAULT value or not */
|
|
bool atthasdef BKI_DEFAULT(f);
|
|
|
|
/* Has a missing value or not */
|
|
bool atthasmissing BKI_DEFAULT(f);
|
|
|
|
/* One of the ATTRIBUTE_IDENTITY_* constants below, or '\0' */
|
|
char attidentity BKI_DEFAULT('\0');
|
|
|
|
/* One of the ATTRIBUTE_GENERATED_* constants below, or '\0' */
|
|
char attgenerated BKI_DEFAULT('\0');
|
|
|
|
/* Is dropped (ie, logically invisible) or not */
|
|
bool attisdropped BKI_DEFAULT(f);
|
|
|
|
/*
|
|
* This flag specifies whether this column has ever had a local
|
|
* definition. It is set for normal non-inherited columns, but also for
|
|
* columns that are inherited from parents if also explicitly listed in
|
|
* CREATE TABLE INHERITS. It is also set when inheritance is removed from
|
|
* a table with ALTER TABLE NO INHERIT. If the flag is set, the column is
|
|
* not dropped by a parent's DROP COLUMN even if this causes the column's
|
|
* attinhcount to become zero.
|
|
*/
|
|
bool attislocal BKI_DEFAULT(t);
|
|
|
|
/* Number of times inherited from direct parent relation(s) */
|
|
int32 attinhcount BKI_DEFAULT(0);
|
|
|
|
/* attribute's collation */
|
|
Oid attcollation;
|
|
|
|
#ifdef CATALOG_VARLEN /* variable-length fields start here */
|
|
/* NOTE: The following fields are not present in tuple descriptors. */
|
|
|
|
/* Column-level access permissions */
|
|
aclitem attacl[1] BKI_DEFAULT(_null_);
|
|
|
|
/* Column-level options */
|
|
text attoptions[1] BKI_DEFAULT(_null_);
|
|
|
|
/* Column-level FDW options */
|
|
text attfdwoptions[1] BKI_DEFAULT(_null_);
|
|
|
|
/*
|
|
* Missing value for added columns. This is a one element array which lets
|
|
* us store a value of the attribute type here.
|
|
*/
|
|
anyarray attmissingval BKI_DEFAULT(_null_);
|
|
#endif
|
|
} FormData_pg_attribute;
|
|
|
|
/*
|
|
* ATTRIBUTE_FIXED_PART_SIZE is the size of the fixed-layout,
|
|
* guaranteed-not-null part of a pg_attribute row. This is in fact as much
|
|
* of the row as gets copied into tuple descriptors, so don't expect you
|
|
* can access fields beyond attcollation except in a real tuple!
|
|
*/
|
|
#define ATTRIBUTE_FIXED_PART_SIZE \
|
|
(offsetof(FormData_pg_attribute,attcollation) + sizeof(Oid))
|
|
|
|
/* ----------------
|
|
* Form_pg_attribute corresponds to a pointer to a tuple with
|
|
* the format of pg_attribute relation.
|
|
* ----------------
|
|
*/
|
|
typedef FormData_pg_attribute *Form_pg_attribute;
|
|
|
|
#ifdef EXPOSE_TO_CLIENT_CODE
|
|
|
|
#define ATTRIBUTE_IDENTITY_ALWAYS 'a'
|
|
#define ATTRIBUTE_IDENTITY_BY_DEFAULT 'd'
|
|
|
|
#define ATTRIBUTE_GENERATED_STORED 's'
|
|
|
|
#endif /* EXPOSE_TO_CLIENT_CODE */
|
|
|
|
#endif /* PG_ATTRIBUTE_H */
|