sequence.c

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/*-------------------------------------------------------------------------
 *
 * sequence.c
 *    Generic routines for sequence-related code.
 *
 * Portions Copyright (c) 1996-2026, PostgreSQL Global Development Group
 * Portions Copyright (c) 1994, Regents of the University of California
 *
 *
 * IDENTIFICATION
 *    src/backend/access/sequence/sequence.c
 *
 *
 * NOTES
 *    This file contains sequence_ routines that implement access to sequences
 *    (in contrast to other relation types like indexes).
 *
 *-------------------------------------------------------------------------
 */
 
#include "postgres.h"
 
#include "access/relation.h"
#include "access/sequence.h"
#include "utils/rel.h"
 
static inline void validate_relation_as_sequence(Relation r);
 
/* ----------------
 *      sequence_open - open a sequence relation by relation OID
 *
 *      This is essentially relation_open plus check that the relation
 *      is a sequence.
 * ----------------
 */
Relation
sequence_open(Oid relationId, LOCKMODE lockmode)
{
    Relation    r;
 
    r = relation_open(relationId, lockmode);
 
    validate_relation_as_sequence(r);
 
    return r;
}
 
/* ----------------
 *      sequence_close - close a sequence
 *
 *      If lockmode is not "NoLock", we then release the specified lock.
 *
 *      Note that it is often sensible to hold a lock beyond relation_close;
 *      in that case, the lock is released automatically at xact end.
 * ----------------
 */
void
sequence_close(Relation relation, LOCKMODE lockmode)
{
    relation_close(relation, lockmode);
}
 
/* ----------------
 *      validate_relation_as_sequence
 *
 *      Make sure relkind is a sequence.
 * ----------------
 */
static inline void
validate_relation_as_sequence(Relation r)
{
    if (r->rd_rel->relkind != RELKIND_SEQUENCE)
        ereport(ERROR,
                (errcode(ERRCODE_WRONG_OBJECT_TYPE),
                 errmsg("\"%s\" is not a sequence",
                        RelationGetRelationName(r))));
}