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Functions

rewriteRemove.h File Reference

#include "nodes/parsenodes.h"
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Functions

void RemoveRewriteRuleById (Oid ruleOid)

Function Documentation

void RemoveRewriteRuleById ( Oid  ruleOid  ) 

Definition at line 38 of file rewriteRemove.c.

References AccessExclusiveLock, BTEqualStrategyNumber, CacheInvalidateRelcache(), elog, ERROR, GETSTRUCT, heap_close, heap_open(), HeapTupleIsValid, NoLock, ObjectIdAttributeNumber, ObjectIdGetDatum, RewriteOidIndexId, RewriteRelationId, RowExclusiveLock, ScanKeyInit(), simple_heap_delete(), SnapshotNow, systable_beginscan(), systable_endscan(), systable_getnext(), and HeapTupleData::t_self.

Referenced by doDeletion().

{
    Relation    RewriteRelation;
    ScanKeyData skey[1];
    SysScanDesc rcscan;
    Relation    event_relation;
    HeapTuple   tuple;
    Oid         eventRelationOid;

    /*
     * Open the pg_rewrite relation.
     */
    RewriteRelation = heap_open(RewriteRelationId, RowExclusiveLock);

    /*
     * Find the tuple for the target rule.
     */
    ScanKeyInit(&skey[0],
                ObjectIdAttributeNumber,
                BTEqualStrategyNumber, F_OIDEQ,
                ObjectIdGetDatum(ruleOid));

    rcscan = systable_beginscan(RewriteRelation, RewriteOidIndexId, true,
                                SnapshotNow, 1, skey);

    tuple = systable_getnext(rcscan);

    if (!HeapTupleIsValid(tuple))
        elog(ERROR, "could not find tuple for rule %u", ruleOid);

    /*
     * We had better grab AccessExclusiveLock to ensure that no queries are
     * going on that might depend on this rule.  (Note: a weaker lock would
     * suffice if it's not an ON SELECT rule.)
     */
    eventRelationOid = ((Form_pg_rewrite) GETSTRUCT(tuple))->ev_class;
    event_relation = heap_open(eventRelationOid, AccessExclusiveLock);

    /*
     * Now delete the pg_rewrite tuple for the rule
     */
    simple_heap_delete(RewriteRelation, &tuple->t_self);

    systable_endscan(rcscan);

    heap_close(RewriteRelation, RowExclusiveLock);

    /*
     * Issue shared-inval notice to force all backends (including me!) to
     * update relcache entries with the new rule set.
     */
    CacheInvalidateRelcache(event_relation);

    /* Close rel, but keep lock till commit... */
    heap_close(event_relation, NoLock);
}