*
* rewriteSupport.cpp
*
*
* Portions Copyright (c) 2020 Huawei Technologies Co.,Ltd.
* Portions Copyright (c) 1996-2012, PostgreSQL Global Development Group
* Portions Copyright (c) 1994, Regents of the University of California
*
*
* IDENTIFICATION
* src/gausskernel/optimizer/rewrite/rewriteSupport.cpp
*
* -------------------------------------------------------------------------
*/
#include "postgres.h"
#include "securec_check.h"
#include "knl/knl_variable.h"
#include "access/sysattr.h"
#include "access/heapam.h"
#include "access/tableam.h"
#include "catalog/indexing.h"
#include "catalog/pg_rewrite.h"
#include "rewrite/rewriteSupport.h"
#include "utils/fmgroids.h"
#include "utils/inval.h"
#include "utils/lsyscache.h"
#include "utils/rel.h"
#include "utils/rel_gs.h"
#include "utils/syscache.h"
#include "utils/snapmgr.h"
* Is there a rule by the given name?
*/
bool IsDefinedRewriteRule(Oid owningRel, const char* ruleName)
{
return SearchSysCacheExists2(RULERELNAME, ObjectIdGetDatum(owningRel), PointerGetDatum(ruleName));
}
* SetRelationRuleStatus
* Set the value of the relation's relhasrules field in pg_class;
* if the relation is becoming a view, also adjust its relkind.
*
* NOTE: caller must be holding an appropriate lock on the relation.
*
* NOTE: an important side-effect of this operation is that an SI invalidation
* message is sent out to all backends --- including me --- causing relcache
* entries to be flushed or updated with the new set of rules for the table.
* This must happen even if we find that no change is needed in the pg_class
* row.
*/
void SetRelationRuleStatus(Oid relationId, bool relHasRules, bool relIsBecomingView)
{
Relation relationRelation;
HeapTuple tuple;
Form_pg_class classForm;
* Find the tuple to update in pg_class, using syscache for the lookup.
*/
relationRelation = heap_open(RelationRelationId, RowExclusiveLock);
tuple = SearchSysCacheCopy1(RELOID, ObjectIdGetDatum(relationId));
if (!HeapTupleIsValid(tuple))
ereport(ERROR,
(errmodule(MOD_OPT_REWRITE),
errcode(ERRCODE_CACHE_LOOKUP_FAILED),
errmsg("cache lookup failed for relation %u", relationId)));
classForm = (Form_pg_class)GETSTRUCT(tuple);
if (classForm->relhasrules != relHasRules || (relIsBecomingView && classForm->relkind != RELKIND_VIEW
&& classForm->relkind != RELKIND_CONTQUERY)) {
classForm->relhasrules = relHasRules;
if (relIsBecomingView)
classForm->relkind = RELKIND_VIEW;
simple_heap_update(relationRelation, &tuple->t_self, tuple);
CatalogUpdateIndexes(relationRelation, tuple);
} else {
CacheInvalidateRelcacheByTuple(tuple);
}
tableam_tops_free_tuple(tuple);
heap_close(relationRelation, RowExclusiveLock);
}
* Find rule oid.
*
* If missing_ok is false, throw an error if rule name not found. If
* true, just return InvalidOid.
*/
Oid get_rewrite_oid(Oid relid, const char* rulename, bool missing_ok)
{
HeapTuple tuple;
Oid ruleoid;
tuple = SearchSysCache2(RULERELNAME, ObjectIdGetDatum(relid), PointerGetDatum(rulename));
if (!HeapTupleIsValid(tuple)) {
if (missing_ok)
return InvalidOid;
ereport(ERROR,
(errcode(ERRCODE_UNDEFINED_OBJECT),
errmsg("rule \"%s\" for relation \"%s\" does not exist", rulename, get_rel_name(relid))));
}
AssertEreport(relid == ((Form_pg_rewrite)GETSTRUCT(tuple))->ev_class, MOD_OPT, "");
ruleoid = HeapTupleGetOid(tuple);
ReleaseSysCache(tuple);
return ruleoid;
}
char* get_rewrite_rulename(Oid ruleid, bool missing_ok)
{
ScanKeyData entry;
SysScanDesc scan;
HeapTuple rewrite_tup;
char* rulename = NULL;
errno_t rc;
Relation rewrite_rel = heap_open(RewriteRelationId, AccessShareLock);
ScanKeyInit(&entry, ObjectIdAttributeNumber, BTEqualStrategyNumber, F_OIDEQ, ObjectIdGetDatum(ruleid));
scan = systable_beginscan(rewrite_rel, RewriteOidIndexId, true, NULL, 1, &entry);
rewrite_tup = systable_getnext(scan);
if (!HeapTupleIsValid(rewrite_tup)) {
if (missing_ok) {
heap_close(rewrite_rel, AccessShareLock);
return NULL;
}
ereport(ERROR,
(errcode(ERRCODE_UNDEFINED_OBJECT),
errmsg("rule \"%u\" does not exist", ruleid)));
}
Form_pg_rewrite pg_rewrite = (Form_pg_rewrite)GETSTRUCT(rewrite_tup);
rulename = (char*)palloc0(NAMEDATALEN);
rc = strncpy_s(rulename, NAMEDATALEN, NameStr(pg_rewrite->rulename), NAMEDATALEN - 1);
securec_check_c(rc, "\0", "\0");
systable_endscan(scan);
heap_close(rewrite_rel, AccessShareLock);
return rulename;
}
* input parameter relid is ev_class, ev_type is pg_rewrite->ev_type, CMD_UTILITY means notify, copy, alter rule,
* latter two is only used in timeseries table redistribution
* ev_type is CmdType, transfer it to char beacuse it is char in system catalog pg_rewrite
*/
bool rel_has_rule(Oid relid, char ev_type)
{
bool has_rule = false;
ScanKeyData entry;
SysScanDesc scan;
HeapTuple rewrite_tup;
Relation rewrite_rel = heap_open(RewriteRelationId, AccessShareLock);
ScanKeyInit(&entry, Anum_pg_rewrite_ev_class, BTEqualStrategyNumber, F_OIDEQ, ObjectIdGetDatum(relid));
scan = systable_beginscan(rewrite_rel, RewriteRelRulenameIndexId, true, NULL, 1, &entry);
while (HeapTupleIsValid((rewrite_tup = systable_getnext(scan)))) {
Form_pg_rewrite pg_rewrite = (Form_pg_rewrite)GETSTRUCT(rewrite_tup);
if (pg_rewrite->ev_type == ev_type) {
has_rule = true;
break;
}
}
systable_endscan(scan);
heap_close(rewrite_rel, AccessShareLock);
return has_rule;
}
* Find rule oid, given only a rule name but no rel OID.
*
* If there's more than one, it's an error. If there aren't any, that's an
* error, too. In general, this should be avoided - it is provided to support
* syntax that is compatible with pre-7.3 versions of PG, where rule names
* were unique across the entire database.
*/
Oid get_rewrite_oid_without_relid(const char* rulename, Oid* reloid, bool missing_ok)
{
Relation RewriteRelation;
TableScanDesc scanDesc;
ScanKeyData scanKeyData;
HeapTuple htup;
Oid ruleoid;
ScanKeyInit(&scanKeyData, Anum_pg_rewrite_rulename, BTEqualStrategyNumber, F_NAMEEQ, CStringGetDatum(rulename));
RewriteRelation = heap_open(RewriteRelationId, AccessShareLock);
scanDesc = tableam_scan_begin(RewriteRelation, SnapshotNow, 1, &scanKeyData);
htup = (HeapTuple) tableam_scan_getnexttuple(scanDesc, ForwardScanDirection);
if (!HeapTupleIsValid(htup)) {
if (!missing_ok)
ereport(ERROR, (errcode(ERRCODE_UNDEFINED_OBJECT), errmsg("rule \"%s\" does not exist", rulename)));
ruleoid = InvalidOid;
} else {
ruleoid = HeapTupleGetOid(htup);
if (reloid != NULL)
*reloid = ((Form_pg_rewrite)GETSTRUCT(htup))->ev_class;
htup = (HeapTuple) tableam_scan_getnexttuple(scanDesc, ForwardScanDirection);
if (HeapTupleIsValid(htup))
ereport(ERROR,
(errcode(ERRCODE_DUPLICATE_OBJECT),
errmsg("there are multiple rules named \"%s\"", rulename),
errhint("Specify a relation name as well as a rule name.")));
}
tableam_scan_end(scanDesc);
heap_close(RewriteRelation, AccessShareLock);
return ruleoid;
}
Oid get_rewrite_relid(Oid ruleid, bool missing_ok)
{
Oid relid;
ScanKeyData entry;
SysScanDesc scan;
HeapTuple rewrite_tup;
Relation rewrite_rel = heap_open(RewriteRelationId, AccessShareLock);
ScanKeyInit(&entry, ObjectIdAttributeNumber, BTEqualStrategyNumber, F_OIDEQ, ObjectIdGetDatum(ruleid));
scan = systable_beginscan(rewrite_rel, RewriteOidIndexId, true, NULL, 1, &entry);
rewrite_tup = systable_getnext(scan);
if (!HeapTupleIsValid(rewrite_tup)) {
if (missing_ok) {
systable_endscan(scan);
heap_close(rewrite_rel, AccessShareLock);
return InvalidOid;
}
ereport(ERROR,
(errcode(ERRCODE_UNDEFINED_OBJECT),
errmsg("rule \"%u\" does not exist", ruleid)));
}
Form_pg_rewrite pg_rewrite = (Form_pg_rewrite)GETSTRUCT(rewrite_tup);
relid = pg_rewrite->ev_class;
systable_endscan(scan);
heap_close(rewrite_rel, AccessShareLock);
return relid;
}