/*------------------------------------------------------------------------- * * pg_attribute.h * definition of the system "attribute" relation (pg_attribute) * along with the relation's initial contents. * * * Portions Copyright (c) 1996-2015, PostgreSQL Global Development Group * Portions Copyright (c) 1994, Regents of the University of California * * src/include/catalog/pg_attribute.h * * NOTES * the genbki.pl script reads this file and generates .bki * information from the DATA() statements. * *------------------------------------------------------------------------- */ #ifndef PG_ATTRIBUTE_H #define PG_ATTRIBUTE_H #include "catalog/genbki.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. * ---------------- */ #define AttributeRelationId 1249 #define AttributeRelation_Rowtype_Id 75 CATALOG(pg_attribute,1249) BKI_BOOTSTRAP BKI_WITHOUT_OIDS BKI_ROWTYPE_OID(75) 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; /* * 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; /* * 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; /* * 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; /* Is dropped (ie, logically invisible) or not */ bool attisdropped; /* * 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; /* Number of times inherited from direct parent relation(s) */ int32 attinhcount; /* 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]; /* Column-level options */ text attoptions[1]; /* Column-level FDW options */ text attfdwoptions[1]; #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; /* ---------------- * compiler constants for pg_attribute * ---------------- */ #define Natts_pg_attribute 21 #define Anum_pg_attribute_attrelid 1 #define Anum_pg_attribute_attname 2 #define Anum_pg_attribute_atttypid 3 #define Anum_pg_attribute_attstattarget 4 #define Anum_pg_attribute_attlen 5 #define Anum_pg_attribute_attnum 6 #define Anum_pg_attribute_attndims 7 #define Anum_pg_attribute_attcacheoff 8 #define Anum_pg_attribute_atttypmod 9 #define Anum_pg_attribute_attbyval 10 #define Anum_pg_attribute_attstorage 11 #define Anum_pg_attribute_attalign 12 #define Anum_pg_attribute_attnotnull 13 #define Anum_pg_attribute_atthasdef 14 #define Anum_pg_attribute_attisdropped 15 #define Anum_pg_attribute_attislocal 16 #define Anum_pg_attribute_attinhcount 17 #define Anum_pg_attribute_attcollation 18 #define Anum_pg_attribute_attacl 19 #define Anum_pg_attribute_attoptions 20 #define Anum_pg_attribute_attfdwoptions 21 /* ---------------- * initial contents of pg_attribute * * The initial contents of pg_attribute are generated at compile time by * genbki.pl. Only "bootstrapped" relations need be included. * ---------------- */ #endif /* PG_ATTRIBUTE_H */