| /*------------------------------------------------------------------------- | |
| * | |
| * 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) 1996-2023, 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. | |
| * | |
| *------------------------------------------------------------------------- | |
| */ | |
| /* ---------------- | |
| * 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 BKI_LOOKUP(pg_class); /* 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. In an entry for a dropped column, this field is set to zero | |
| * since the pg_type entry may no longer exist; but we rely on attlen, | |
| * attbyval, and attalign to still tell us how large the values in the | |
| * table are. | |
| */ | |
| Oid atttypid BKI_LOOKUP_OPT(pg_type); | |
| /* | |
| * 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; | |
| /* | |
| * 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); | |
| /* | |
| * attndims is the declared number of dimensions, if an array type, | |
| * otherwise zero. | |
| */ | |
| int16 attndims; | |
| /* | |
| * attbyval is a copy of the typbyval field from pg_type for this | |
| * attribute. See atttypid comments above. | |
| */ | |
| bool attbyval; | |
| /* | |
| * attalign is a copy of the typalign field from pg_type for this | |
| * attribute. See atttypid comments above. | |
| */ | |
| char attalign; | |
| /*---------- | |
| * 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 as for pg_type.typstorage (see TYPSTORAGE macros). | |
| *---------- | |
| */ | |
| char attstorage; | |
| /* | |
| * attcompression sets the current compression method of the attribute. | |
| * Typically this is InvalidCompressionMethod ('\0') to specify use of the | |
| * current default setting (see default_toast_compression). Otherwise, | |
| * 'p' selects pglz compression, while 'l' selects LZ4 compression. | |
| * However, this field is ignored whenever attstorage does not allow | |
| * compression. | |
| */ | |
| char attcompression BKI_DEFAULT('\0'); | |
| /* 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) */ | |
| int16 attinhcount BKI_DEFAULT(0); | |
| /* | |
| * 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. | |
| * | |
| * int16 is sufficient because the max value is currently 10000. | |
| */ | |
| int16 attstattarget BKI_DEFAULT(-1); | |
| /* attribute's collation, if any */ | |
| Oid attcollation BKI_LOOKUP_OPT(pg_collation); | |
| /* 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_); | |
| } 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 the variable-length fields except in a real tuple! | |
| */ | |
| /* ---------------- | |
| * Form_pg_attribute corresponds to a pointer to a tuple with | |
| * the format of pg_attribute relation. | |
| * ---------------- | |
| */ | |
| typedef FormData_pg_attribute *Form_pg_attribute; | |
| DECLARE_UNIQUE_INDEX(pg_attribute_relid_attnam_index, 2658, AttributeRelidNameIndexId, on pg_attribute using btree(attrelid oid_ops, attname name_ops)); | |
| DECLARE_UNIQUE_INDEX_PKEY(pg_attribute_relid_attnum_index, 2659, AttributeRelidNumIndexId, on pg_attribute using btree(attrelid oid_ops, attnum int2_ops)); | |