codekingpro/portable-devtools

1/*-------------------------------------------------------------------------2 *3 * pg_attribute.h4 *	  definition of the "attribute" system catalog (pg_attribute)5 *6 * The initial contents of pg_attribute are generated at compile time by7 * genbki.pl, so there is no pg_attribute.dat file.  Only "bootstrapped"8 * relations need be included.9 *10 *11 * Portions Copyright (c) 1996-2023, PostgreSQL Global Development Group12 * Portions Copyright (c) 1994, Regents of the University of California13 *14 * src/include/catalog/pg_attribute.h15 *16 * NOTES17 *	  The Catalog.pm module reads this file and derives schema18 *	  information.19 *20 *-------------------------------------------------------------------------21 */22#ifndef PG_ATTRIBUTE_H23#define PG_ATTRIBUTE_H24 25#include "catalog/genbki.h"26#include "catalog/pg_attribute_d.h"27 28/* ----------------29 *		pg_attribute definition.  cpp turns this into30 *		typedef struct FormData_pg_attribute31 *32 *		If you change the following, make sure you change the structs for33 *		system attributes in catalog/heap.c also.34 *		You may need to change catalog/genbki.pl as well.35 * ----------------36 */37CATALOG(pg_attribute,1249,AttributeRelationId) BKI_BOOTSTRAP BKI_ROWTYPE_OID(75,AttributeRelation_Rowtype_Id) BKI_SCHEMA_MACRO38{39	Oid			attrelid BKI_LOOKUP(pg_class);	/* OID of relation containing40												 * this attribute */41	NameData	attname;		/* name of attribute */42 43	/*44	 * atttypid is the OID of the instance in Catalog Class pg_type that45	 * defines the data type of this attribute (e.g. int4).  Information in46	 * that instance is redundant with the attlen, attbyval, and attalign47	 * attributes of this instance, so they had better match or Postgres will48	 * fail.  In an entry for a dropped column, this field is set to zero49	 * since the pg_type entry may no longer exist; but we rely on attlen,50	 * attbyval, and attalign to still tell us how large the values in the51	 * table are.52	 */53	Oid			atttypid BKI_LOOKUP_OPT(pg_type);54 55	/*56	 * attlen is a copy of the typlen field from pg_type for this attribute.57	 * See atttypid comments above.58	 */59	int16		attlen;60 61	/*62	 * attnum is the "attribute number" for the attribute:	A value that63	 * uniquely identifies this attribute within its class. For user64	 * attributes, Attribute numbers are greater than 0 and not greater than65	 * the number of attributes in the class. I.e. if the Class pg_class says66	 * that Class XYZ has 10 attributes, then the user attribute numbers in67	 * Class pg_attribute must be 1-10.68	 *69	 * System attributes have attribute numbers less than 0 that are unique70	 * within the class, but not constrained to any particular range.71	 *72	 * Note that (attnum - 1) is often used as the index to an array.73	 */74	int16		attnum;75 76	/*77	 * fastgetattr() uses attcacheoff to cache byte offsets of attributes in78	 * heap tuples.  The value actually stored in pg_attribute (-1) indicates79	 * no cached value.  But when we copy these tuples into a tuple80	 * descriptor, we may then update attcacheoff in the copies. This speeds81	 * up the attribute walking process.82	 */83	int32		attcacheoff BKI_DEFAULT(-1);84 85	/*86	 * atttypmod records type-specific data supplied at table creation time87	 * (for example, the max length of a varchar field).  It is passed to88	 * type-specific input and output functions as the third argument. The89	 * value will generally be -1 for types that do not need typmod.90	 */91	int32		atttypmod BKI_DEFAULT(-1);92 93	/*94	 * attndims is the declared number of dimensions, if an array type,95	 * otherwise zero.96	 */97	int16		attndims;98 99	/*100	 * attbyval is a copy of the typbyval field from pg_type for this101	 * attribute.  See atttypid comments above.102	 */103	bool		attbyval;104 105	/*106	 * attalign is a copy of the typalign field from pg_type for this107	 * attribute.  See atttypid comments above.108	 */109	char		attalign;110 111	/*----------112	 * attstorage tells for VARLENA attributes, what the heap access113	 * methods can do to it if a given tuple doesn't fit into a page.114	 * Possible values are as for pg_type.typstorage (see TYPSTORAGE macros).115	 *----------116	 */117	char		attstorage;118 119	/*120	 * attcompression sets the current compression method of the attribute.121	 * Typically this is InvalidCompressionMethod ('\0') to specify use of the122	 * current default setting (see default_toast_compression).  Otherwise,123	 * 'p' selects pglz compression, while 'l' selects LZ4 compression.124	 * However, this field is ignored whenever attstorage does not allow125	 * compression.126	 */127	char		attcompression BKI_DEFAULT('\0');128 129	/* This flag represents the "NOT NULL" constraint */130	bool		attnotnull;131 132	/* Has DEFAULT value or not */133	bool		atthasdef BKI_DEFAULT(f);134 135	/* Has a missing value or not */136	bool		atthasmissing BKI_DEFAULT(f);137 138	/* One of the ATTRIBUTE_IDENTITY_* constants below, or '\0' */139	char		attidentity BKI_DEFAULT('\0');140 141	/* One of the ATTRIBUTE_GENERATED_* constants below, or '\0' */142	char		attgenerated BKI_DEFAULT('\0');143 144	/* Is dropped (ie, logically invisible) or not */145	bool		attisdropped BKI_DEFAULT(f);146 147	/*148	 * This flag specifies whether this column has ever had a local149	 * definition.  It is set for normal non-inherited columns, but also for150	 * columns that are inherited from parents if also explicitly listed in151	 * CREATE TABLE INHERITS.  It is also set when inheritance is removed from152	 * a table with ALTER TABLE NO INHERIT.  If the flag is set, the column is153	 * not dropped by a parent's DROP COLUMN even if this causes the column's154	 * attinhcount to become zero.155	 */156	bool		attislocal BKI_DEFAULT(t);157 158	/* Number of times inherited from direct parent relation(s) */159	int16		attinhcount BKI_DEFAULT(0);160 161	/*162	 * attstattarget is the target number of statistics datapoints to collect163	 * during VACUUM ANALYZE of this column.  A zero here indicates that we do164	 * not wish to collect any stats about this column. A "-1" here indicates165	 * that no value has been explicitly set for this column, so ANALYZE166	 * should use the default setting.167	 *168	 * int16 is sufficient because the max value is currently 10000.169	 */170	int16		attstattarget BKI_DEFAULT(-1);171 172	/* attribute's collation, if any */173	Oid			attcollation BKI_LOOKUP_OPT(pg_collation);174 175#ifdef CATALOG_VARLEN			/* variable-length fields start here */176	/* NOTE: The following fields are not present in tuple descriptors. */177 178	/* Column-level access permissions */179	aclitem		attacl[1] BKI_DEFAULT(_null_);180 181	/* Column-level options */182	text		attoptions[1] BKI_DEFAULT(_null_);183 184	/* Column-level FDW options */185	text		attfdwoptions[1] BKI_DEFAULT(_null_);186 187	/*188	 * Missing value for added columns. This is a one element array which lets189	 * us store a value of the attribute type here.190	 */191	anyarray	attmissingval BKI_DEFAULT(_null_);192#endif193} FormData_pg_attribute;194 195/*196 * ATTRIBUTE_FIXED_PART_SIZE is the size of the fixed-layout,197 * guaranteed-not-null part of a pg_attribute row.  This is in fact as much198 * of the row as gets copied into tuple descriptors, so don't expect you199 * can access the variable-length fields except in a real tuple!200 */201#define ATTRIBUTE_FIXED_PART_SIZE \202	(offsetof(FormData_pg_attribute,attcollation) + sizeof(Oid))203 204/* ----------------205 *		Form_pg_attribute corresponds to a pointer to a tuple with206 *		the format of pg_attribute relation.207 * ----------------208 */209typedef FormData_pg_attribute *Form_pg_attribute;210 211DECLARE_UNIQUE_INDEX(pg_attribute_relid_attnam_index, 2658, AttributeRelidNameIndexId, on pg_attribute using btree(attrelid oid_ops, attname name_ops));212DECLARE_UNIQUE_INDEX_PKEY(pg_attribute_relid_attnum_index, 2659, AttributeRelidNumIndexId, on pg_attribute using btree(attrelid oid_ops, attnum int2_ops));213 214#ifdef EXPOSE_TO_CLIENT_CODE215 216#define		  ATTRIBUTE_IDENTITY_ALWAYS		'a'217#define		  ATTRIBUTE_IDENTITY_BY_DEFAULT 'd'218 219#define		  ATTRIBUTE_GENERATED_STORED	's'220 221#endif							/* EXPOSE_TO_CLIENT_CODE */222 223#endif							/* PG_ATTRIBUTE_H */224