pg_class.h

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/*-------------------------------------------------------------------------
 *
 * pg_class.h
 *    definition of the "relation" system catalog (pg_class)
 *
 *
 * Portions Copyright (c) 1996-2026, PostgreSQL Global Development Group
 * Portions Copyright (c) 1994, Regents of the University of California
 *
 * src/include/catalog/pg_class.h
 *
 * NOTES
 *    The Catalog.pm module reads this file and derives schema
 *    information.
 *
 *-------------------------------------------------------------------------
 */
#ifndef PG_CLASS_H
#define PG_CLASS_H
 
#include "catalog/genbki.h"
#include "catalog/pg_class_d.h" /* IWYU pragma: export */
 
/* ----------------
 *      pg_class definition.  cpp turns this into
 *      typedef struct FormData_pg_class
 *
 * Note that the BKI_DEFAULT values below are only used for rows describing
 * BKI_BOOTSTRAP catalogs, since only those rows appear in pg_class.dat.
 * ----------------
 */
BEGIN_CATALOG_STRUCT
 
CATALOG(pg_class,1259,RelationRelationId) BKI_BOOTSTRAP BKI_ROWTYPE_OID(83,RelationRelation_Rowtype_Id) BKI_SCHEMA_MACRO
{
    /* oid */
    Oid         oid;
 
    /* class name */
    NameData    relname;
 
    /* OID of namespace containing this class */
    Oid         relnamespace BKI_DEFAULT(pg_catalog) BKI_LOOKUP(pg_namespace);
 
    /* OID of entry in pg_type for relation's implicit row type, if any */
    Oid         reltype BKI_LOOKUP_OPT(pg_type);
 
    /* OID of entry in pg_type for underlying composite type, if any */
    Oid         reloftype BKI_DEFAULT(0) BKI_LOOKUP_OPT(pg_type);
 
    /* class owner */
    Oid         relowner BKI_DEFAULT(POSTGRES) BKI_LOOKUP(pg_authid);
 
    /* access method; 0 if not a table / index */
    Oid         relam BKI_DEFAULT(heap) BKI_LOOKUP_OPT(pg_am);
 
    /* identifier of physical storage file */
    /* relfilenode == 0 means it is a "mapped" relation, see relmapper.c */
    Oid         relfilenode BKI_DEFAULT(0);
 
    /* identifier of table space for relation (0 means default for database) */
    Oid         reltablespace BKI_DEFAULT(0) BKI_LOOKUP_OPT(pg_tablespace);
 
    /* # of blocks (not always up-to-date) */
    int32       relpages BKI_DEFAULT(0);
 
    /* # of tuples (not always up-to-date; -1 means "unknown") */
    float4      reltuples BKI_DEFAULT(-1);
 
    /* # of all-visible blocks (not always up-to-date) */
    int32       relallvisible BKI_DEFAULT(0);
 
    /* # of all-frozen blocks (not always up-to-date) */
    int32       relallfrozen BKI_DEFAULT(0);
 
    /* OID of toast table; 0 if none */
    Oid         reltoastrelid BKI_DEFAULT(0) BKI_LOOKUP_OPT(pg_class);
 
    /* T if has (or has had) any indexes */
    bool        relhasindex BKI_DEFAULT(f);
 
    /* T if shared across databases */
    bool        relisshared BKI_DEFAULT(f);
 
    /* see RELPERSISTENCE_xxx constants below */
    char        relpersistence BKI_DEFAULT(p);
 
    /* see RELKIND_xxx constants below */
    char        relkind BKI_DEFAULT(r);
 
    /* number of user attributes */
    int16       relnatts BKI_DEFAULT(0);    /* genbki.pl will fill this in */
 
    /*
     * Class pg_attribute must contain exactly "relnatts" user attributes
     * (with attnums ranging from 1 to relnatts) for this class.  It may also
     * contain entries with negative attnums for system attributes.
     */
 
    /* # of CHECK constraints for class */
    int16       relchecks BKI_DEFAULT(0);
 
    /* has (or has had) any rules */
    bool        relhasrules BKI_DEFAULT(f);
 
    /* has (or has had) any TRIGGERs */
    bool        relhastriggers BKI_DEFAULT(f);
 
    /* has (or has had) child tables or indexes */
    bool        relhassubclass BKI_DEFAULT(f);
 
    /* row security is enabled or not */
    bool        relrowsecurity BKI_DEFAULT(f);
 
    /* row security forced for owners or not */
    bool        relforcerowsecurity BKI_DEFAULT(f);
 
    /* matview currently holds query results */
    bool        relispopulated BKI_DEFAULT(t);
 
    /* see REPLICA_IDENTITY_xxx constants */
    char        relreplident BKI_DEFAULT(n);
 
    /* is relation a partition? */
    bool        relispartition BKI_DEFAULT(f);
 
    /* link to original rel during table rewrite; otherwise 0 */
    Oid         relrewrite BKI_DEFAULT(0) BKI_LOOKUP_OPT(pg_class);
 
    /* all Xids < this are frozen in this rel */
    TransactionId relfrozenxid BKI_DEFAULT(3);  /* FirstNormalTransactionId */
 
    /* all multixacts in this rel are >= this; it is really a MultiXactId */
    TransactionId relminmxid BKI_DEFAULT(1);    /* FirstMultiXactId */
 
#ifdef CATALOG_VARLEN           /* variable-length fields start here */
    /* NOTE: These fields are not present in a relcache entry's rd_rel field. */
    /* access permissions */
    aclitem     relacl[1] BKI_DEFAULT(_null_);
 
    /* access-method-specific options */
    text        reloptions[1] BKI_DEFAULT(_null_);
 
    /* partition bound node tree */
    pg_node_tree relpartbound BKI_DEFAULT(_null_);
#endif
} FormData_pg_class;
 
END_CATALOG_STRUCT
 
/* Size of fixed part of pg_class tuples, not counting var-length fields */
#define CLASS_TUPLE_SIZE \
     (offsetof(FormData_pg_class,relminmxid) + sizeof(TransactionId))
 
/* ----------------
 *      Form_pg_class corresponds to a pointer to a tuple with
 *      the format of pg_class relation.
 * ----------------
 */
typedef FormData_pg_class *Form_pg_class;
 
DECLARE_UNIQUE_INDEX_PKEY(pg_class_oid_index, 2662, ClassOidIndexId, pg_class, btree(oid oid_ops));
DECLARE_UNIQUE_INDEX(pg_class_relname_nsp_index, 2663, ClassNameNspIndexId, pg_class, btree(relname name_ops, relnamespace oid_ops));
DECLARE_INDEX(pg_class_tblspc_relfilenode_index, 3455, ClassTblspcRelfilenodeIndexId, pg_class, btree(reltablespace oid_ops, relfilenode oid_ops));
 
MAKE_SYSCACHE(RELOID, pg_class_oid_index, 128);
MAKE_SYSCACHE(RELNAMENSP, pg_class_relname_nsp_index, 128);
 
#ifdef EXPOSE_TO_CLIENT_CODE
 
#define       RELKIND_RELATION        'r'   /* ordinary table */
#define       RELKIND_INDEX           'i'   /* secondary index */
#define       RELKIND_SEQUENCE        'S'   /* sequence object */
#define       RELKIND_TOASTVALUE      't'   /* for out-of-line values */
#define       RELKIND_VIEW            'v'   /* view */
#define       RELKIND_MATVIEW         'm'   /* materialized view */
#define       RELKIND_COMPOSITE_TYPE  'c'   /* composite type */
#define       RELKIND_FOREIGN_TABLE   'f'   /* foreign table */
#define       RELKIND_PARTITIONED_TABLE 'p' /* partitioned table */
#define       RELKIND_PARTITIONED_INDEX 'I' /* partitioned index */
 
#define       RELPERSISTENCE_PERMANENT  'p' /* regular table */
#define       RELPERSISTENCE_UNLOGGED   'u' /* unlogged permanent table */
#define       RELPERSISTENCE_TEMP       't' /* temporary table */
 
/* default selection for replica identity (primary key or nothing) */
#define       REPLICA_IDENTITY_DEFAULT  'd'
/* no replica identity is logged for this relation */
#define       REPLICA_IDENTITY_NOTHING  'n'
/* all columns are logged as replica identity */
#define       REPLICA_IDENTITY_FULL     'f'
/*
 * an explicitly chosen candidate key's columns are used as replica identity.
 * Note this will still be set if the index has been dropped; in that case it
 * has the same meaning as 'n'.
 */
#define       REPLICA_IDENTITY_INDEX    'i'
 
/*
 * Relation kinds that have physical storage. These relations normally have
 * relfilenode set to non-zero, but it can also be zero if the relation is
 * mapped.
 */
#define RELKIND_HAS_STORAGE(relkind) \
    ((relkind) == RELKIND_RELATION || \
     (relkind) == RELKIND_INDEX || \
     (relkind) == RELKIND_SEQUENCE || \
     (relkind) == RELKIND_TOASTVALUE || \
     (relkind) == RELKIND_MATVIEW)
 
#define RELKIND_HAS_PARTITIONS(relkind) \
    ((relkind) == RELKIND_PARTITIONED_TABLE || \
     (relkind) == RELKIND_PARTITIONED_INDEX)
 
/*
 * Relation kinds that support tablespaces: All relation kinds with storage
 * support tablespaces, except that we don't support moving sequences around
 * into different tablespaces.  Partitioned tables and indexes don't have
 * physical storage, but they have a tablespace settings so that their
 * children can inherit it.
 */
#define RELKIND_HAS_TABLESPACE(relkind) \
    ((RELKIND_HAS_STORAGE(relkind) || RELKIND_HAS_PARTITIONS(relkind)) \
     && (relkind) != RELKIND_SEQUENCE)
 
/*
 * Relation kinds with a table access method (rd_tableam).  Although sequences
 * use the heap table AM, they are enough of a special case in most uses that
 * they are not included here.  Likewise, partitioned tables can have an access
 * method defined so that their partitions can inherit it, but they do not set
 * rd_tableam; hence, this is handled specially outside of this macro.
 */
#define RELKIND_HAS_TABLE_AM(relkind) \
    ((relkind) == RELKIND_RELATION || \
     (relkind) == RELKIND_TOASTVALUE || \
     (relkind) == RELKIND_MATVIEW)
 
#endif                          /* EXPOSE_TO_CLIENT_CODE */
 
extern int  errdetail_relkind_not_supported(char relkind);
 
#endif                          /* PG_CLASS_H */