Header And Logo
|
#include "nodes/parsenodes.h"#include "utils/relcache.h"
Go to the source code of this file.
Defines | |
| #define | RULE_FIRES_ON_ORIGIN 'O' |
| #define | RULE_FIRES_ALWAYS 'A' |
| #define | RULE_FIRES_ON_REPLICA 'R' |
| #define | RULE_DISABLED 'D' |
Functions | |
| Oid | DefineRule (RuleStmt *stmt, const char *queryString) |
| Oid | DefineQueryRewrite (char *rulename, Oid event_relid, Node *event_qual, CmdType event_type, bool is_instead, bool replace, List *action) |
| Oid | RenameRewriteRule (RangeVar *relation, const char *oldName, const char *newName) |
| void | setRuleCheckAsUser (Node *node, Oid userid) |
| void | EnableDisableRule (Relation rel, const char *rulename, char fires_when) |
| #define RULE_DISABLED 'D' |
Definition at line 23 of file rewriteDefine.h.
Referenced by ATExecCmd(), and matchLocks().
| #define RULE_FIRES_ALWAYS 'A' |
Definition at line 21 of file rewriteDefine.h.
Referenced by ATExecCmd().
| #define RULE_FIRES_ON_ORIGIN 'O' |
Definition at line 20 of file rewriteDefine.h.
Referenced by ATExecCmd(), InsertRule(), and matchLocks().
| #define RULE_FIRES_ON_REPLICA 'R' |
Definition at line 22 of file rewriteDefine.h.
Referenced by ATExecCmd(), and matchLocks().
| Oid DefineQueryRewrite | ( | char * | rulename, | |
| Oid | event_relid, | |||
| Node * | event_qual, | |||
| CmdType | event_type, | |||
| bool | is_instead, | |||
| bool | replace, | |||
| List * | action | |||
| ) |
Definition at line 231 of file rewriteDefine.c.
References AccessExclusiveLock, ACL_KIND_CLASS, aclcheck_error(), ACLCHECK_NOT_OWNER, allowSystemTableMods, CatalogUpdateIndexes(), checkRuleResultList(), ObjectAddress::classId, CMD_SELECT, CommandCounterIncrement(), Query::commandType, deleteDependencyRecordsFor(), DeleteSystemAttributeTuples(), DROP_RESTRICT, elog, ereport, errcode(), errhint(), errmsg(), ERROR, RewriteRule::event, ForwardScanDirection, getInsertSelectQuery(), GETSTRUCT, GetUserId(), Query::hasModifyingCTE, heap_beginscan(), heap_close, heap_endscan(), heap_freetuple(), heap_getnext(), heap_open(), HeapTupleIsValid, i, InsertRule(), IsSystemRelation(), lfirst, linitial, list_length(), NAMEDATALEN, NIL, NoLock, NULL, RuleLock::numLocks, ObjectAddress::objectId, ObjectIdGetDatum, ObjectAddress::objectSubId, OidIsValid, PERFORM_DELETION_INTERNAL, performDeletion(), pg_class_ownercheck(), PRS2_NEW_VARNO, PRS2_OLD_VARNO, pstrdup(), RelationData::rd_rel, RelationData::rd_rules, RelationDropStorage(), RelationGetDescr, RelationGetRelationName, RelationRelationId, RELKIND_MATVIEW, RELKIND_RELATION, RELKIND_VIEW, RELOID, Query::resultRelation, Query::returningList, RowExclusiveLock, RuleLock::rules, SearchSysCacheCopy1, SetRelationRuleStatus(), simple_heap_update(), SnapshotNow, HeapTupleData::t_self, Query::targetList, Query::utilityStmt, and ViewSelectRuleName.
Referenced by DefineRule(), and DefineViewRules().
{
Relation event_relation;
int event_attno;
ListCell *l;
Query *query;
bool RelisBecomingView = false;
Oid ruleId = InvalidOid;
/*
* If we are installing an ON SELECT rule, we had better grab
* AccessExclusiveLock to ensure no SELECTs are currently running on the
* event relation. For other types of rules, it would be sufficient to
* grab ShareRowExclusiveLock to lock out insert/update/delete actions and
* to ensure that we lock out current CREATE RULE statements; but because
* of race conditions in access to catalog entries, we can't do that yet.
*
* Note that this lock level should match the one used in DefineRule.
*/
event_relation = heap_open(event_relid, AccessExclusiveLock);
/*
* Verify relation is of a type that rules can sensibly be applied to.
*/
if (event_relation->rd_rel->relkind != RELKIND_RELATION &&
event_relation->rd_rel->relkind != RELKIND_MATVIEW &&
event_relation->rd_rel->relkind != RELKIND_VIEW)
ereport(ERROR,
(errcode(ERRCODE_WRONG_OBJECT_TYPE),
errmsg("\"%s\" is not a table or view",
RelationGetRelationName(event_relation))));
if (!allowSystemTableMods && IsSystemRelation(event_relation))
ereport(ERROR,
(errcode(ERRCODE_INSUFFICIENT_PRIVILEGE),
errmsg("permission denied: \"%s\" is a system catalog",
RelationGetRelationName(event_relation))));
/*
* Check user has permission to apply rules to this relation.
*/
if (!pg_class_ownercheck(event_relid, GetUserId()))
aclcheck_error(ACLCHECK_NOT_OWNER, ACL_KIND_CLASS,
RelationGetRelationName(event_relation));
/*
* No rule actions that modify OLD or NEW
*/
foreach(l, action)
{
query = (Query *) lfirst(l);
if (query->resultRelation == 0)
continue;
/* Don't be fooled by INSERT/SELECT */
if (query != getInsertSelectQuery(query, NULL))
continue;
if (query->resultRelation == PRS2_OLD_VARNO)
ereport(ERROR,
(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
errmsg("rule actions on OLD are not implemented"),
errhint("Use views or triggers instead.")));
if (query->resultRelation == PRS2_NEW_VARNO)
ereport(ERROR,
(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
errmsg("rule actions on NEW are not implemented"),
errhint("Use triggers instead.")));
}
if (event_type == CMD_SELECT)
{
/*
* Rules ON SELECT are restricted to view definitions
*
* So there cannot be INSTEAD NOTHING, ...
*/
if (list_length(action) == 0)
ereport(ERROR,
(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
errmsg("INSTEAD NOTHING rules on SELECT are not implemented"),
errhint("Use views instead.")));
/*
* ... there cannot be multiple actions, ...
*/
if (list_length(action) > 1)
ereport(ERROR,
(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
errmsg("multiple actions for rules on SELECT are not implemented")));
/*
* ... the one action must be a SELECT, ...
*/
query = (Query *) linitial(action);
if (!is_instead ||
query->commandType != CMD_SELECT ||
query->utilityStmt != NULL)
ereport(ERROR,
(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
errmsg("rules on SELECT must have action INSTEAD SELECT")));
/*
* ... it cannot contain data-modifying WITH ...
*/
if (query->hasModifyingCTE)
ereport(ERROR,
(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
errmsg("rules on SELECT must not contain data-modifying statements in WITH")));
/*
* ... there can be no rule qual, ...
*/
if (event_qual != NULL)
ereport(ERROR,
(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
errmsg("event qualifications are not implemented for rules on SELECT")));
/*
* ... the targetlist of the SELECT action must exactly match the
* event relation, ...
*/
checkRuleResultList(query->targetList,
RelationGetDescr(event_relation),
true);
/*
* ... there must not be another ON SELECT rule already ...
*/
if (!replace && event_relation->rd_rules != NULL)
{
int i;
for (i = 0; i < event_relation->rd_rules->numLocks; i++)
{
RewriteRule *rule;
rule = event_relation->rd_rules->rules[i];
if (rule->event == CMD_SELECT)
ereport(ERROR,
(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
errmsg("\"%s\" is already a view",
RelationGetRelationName(event_relation))));
}
}
/*
* ... and finally the rule must be named _RETURN.
*/
if (strcmp(rulename, ViewSelectRuleName) != 0)
{
/*
* In versions before 7.3, the expected name was _RETviewname. For
* backwards compatibility with old pg_dump output, accept that
* and silently change it to _RETURN. Since this is just a quick
* backwards-compatibility hack, limit the number of characters
* checked to a few less than NAMEDATALEN; this saves having to
* worry about where a multibyte character might have gotten
* truncated.
*/
if (strncmp(rulename, "_RET", 4) != 0 ||
strncmp(rulename + 4, RelationGetRelationName(event_relation),
NAMEDATALEN - 4 - 4) != 0)
ereport(ERROR,
(errcode(ERRCODE_INVALID_OBJECT_DEFINITION),
errmsg("view rule for \"%s\" must be named \"%s\"",
RelationGetRelationName(event_relation),
ViewSelectRuleName)));
rulename = pstrdup(ViewSelectRuleName);
}
/*
* Are we converting a relation to a view?
*
* If so, check that the relation is empty because the storage for the
* relation is going to be deleted. Also insist that the rel not have
* any triggers, indexes, or child tables. (Note: these tests are too
* strict, because they will reject relations that once had such but
* don't anymore. But we don't really care, because this whole
* business of converting relations to views is just a kluge to allow
* dump/reload of views that participate in circular dependencies.)
*/
if (event_relation->rd_rel->relkind != RELKIND_VIEW &&
event_relation->rd_rel->relkind != RELKIND_MATVIEW)
{
HeapScanDesc scanDesc;
scanDesc = heap_beginscan(event_relation, SnapshotNow, 0, NULL);
if (heap_getnext(scanDesc, ForwardScanDirection) != NULL)
ereport(ERROR,
(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
errmsg("could not convert table \"%s\" to a view because it is not empty",
RelationGetRelationName(event_relation))));
heap_endscan(scanDesc);
if (event_relation->rd_rel->relhastriggers)
ereport(ERROR,
(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
errmsg("could not convert table \"%s\" to a view because it has triggers",
RelationGetRelationName(event_relation)),
errhint("In particular, the table cannot be involved in any foreign key relationships.")));
if (event_relation->rd_rel->relhasindex)
ereport(ERROR,
(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
errmsg("could not convert table \"%s\" to a view because it has indexes",
RelationGetRelationName(event_relation))));
if (event_relation->rd_rel->relhassubclass)
ereport(ERROR,
(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
errmsg("could not convert table \"%s\" to a view because it has child tables",
RelationGetRelationName(event_relation))));
RelisBecomingView = true;
}
}
else
{
/*
* For non-SELECT rules, a RETURNING list can appear in at most one of
* the actions ... and there can't be any RETURNING list at all in a
* conditional or non-INSTEAD rule. (Actually, there can be at most
* one RETURNING list across all rules on the same event, but it seems
* best to enforce that at rule expansion time.) If there is a
* RETURNING list, it must match the event relation.
*/
bool haveReturning = false;
foreach(l, action)
{
query = (Query *) lfirst(l);
if (!query->returningList)
continue;
if (haveReturning)
ereport(ERROR,
(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
errmsg("cannot have multiple RETURNING lists in a rule")));
haveReturning = true;
if (event_qual != NULL)
ereport(ERROR,
(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
errmsg("RETURNING lists are not supported in conditional rules")));
if (!is_instead)
ereport(ERROR,
(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
errmsg("RETURNING lists are not supported in non-INSTEAD rules")));
checkRuleResultList(query->returningList,
RelationGetDescr(event_relation),
false);
}
}
/*
* This rule is allowed - prepare to install it.
*/
event_attno = -1;
/* discard rule if it's null action and not INSTEAD; it's a no-op */
if (action != NIL || is_instead)
{
ruleId = InsertRule(rulename,
event_type,
event_relid,
event_attno,
is_instead,
event_qual,
action,
replace);
/*
* Set pg_class 'relhasrules' field TRUE for event relation.
*
* Important side effect: an SI notice is broadcast to force all
* backends (including me!) to update relcache entries with the new
* rule.
*/
SetRelationRuleStatus(event_relid, true);
}
/* ---------------------------------------------------------------------
* If the relation is becoming a view:
* - delete the associated storage files
* - get rid of any system attributes in pg_attribute; a view shouldn't
* have any of those
* - remove the toast table; there is no need for it anymore, and its
* presence would make vacuum slightly more complicated
* - set relkind to RELKIND_VIEW, and adjust other pg_class fields
* to be appropriate for a view
*
* NB: we had better have AccessExclusiveLock to do this ...
* ---------------------------------------------------------------------
*/
if (RelisBecomingView)
{
Relation relationRelation;
Oid toastrelid;
HeapTuple classTup;
Form_pg_class classForm;
relationRelation = heap_open(RelationRelationId, RowExclusiveLock);
toastrelid = event_relation->rd_rel->reltoastrelid;
/* drop storage while table still looks like a table */
RelationDropStorage(event_relation);
DeleteSystemAttributeTuples(event_relid);
/*
* Drop the toast table if any. (This won't take care of updating
* the toast fields in the relation's own pg_class entry; we handle
* that below.)
*/
if (OidIsValid(toastrelid))
{
ObjectAddress toastobject;
/*
* Delete the dependency of the toast relation on the main
* relation so we can drop the former without dropping the latter.
*/
deleteDependencyRecordsFor(RelationRelationId, toastrelid,
false);
/* Make deletion of dependency record visible */
CommandCounterIncrement();
/* Now drop toast table, including its index */
toastobject.classId = RelationRelationId;
toastobject.objectId = toastrelid;
toastobject.objectSubId = 0;
performDeletion(&toastobject, DROP_RESTRICT,
PERFORM_DELETION_INTERNAL);
}
/*
* SetRelationRuleStatus may have updated the pg_class row, so we must
* advance the command counter before trying to update it again.
*/
CommandCounterIncrement();
/*
* Fix pg_class entry to look like a normal view's, including setting
* the correct relkind and removal of reltoastrelid/reltoastidxid of
* the toast table we potentially removed above.
*/
classTup = SearchSysCacheCopy1(RELOID, ObjectIdGetDatum(event_relid));
if (!HeapTupleIsValid(classTup))
elog(ERROR, "cache lookup failed for relation %u", event_relid);
classForm = (Form_pg_class) GETSTRUCT(classTup);
classForm->reltablespace = InvalidOid;
classForm->relpages = 0;
classForm->reltuples = 0;
classForm->relallvisible = 0;
classForm->reltoastrelid = InvalidOid;
classForm->reltoastidxid = InvalidOid;
classForm->relhasindex = false;
classForm->relkind = RELKIND_VIEW;
classForm->relhasoids = false;
classForm->relhaspkey = false;
classForm->relfrozenxid = InvalidTransactionId;
classForm->relminmxid = InvalidMultiXactId;
simple_heap_update(relationRelation, &classTup->t_self, classTup);
CatalogUpdateIndexes(relationRelation, classTup);
heap_freetuple(classTup);
heap_close(relationRelation, RowExclusiveLock);
}
/* Close rel, but keep lock till commit... */
heap_close(event_relation, NoLock);
return ruleId;
}
Definition at line 197 of file rewriteDefine.c.
References AccessExclusiveLock, DefineQueryRewrite(), RuleStmt::event, RuleStmt::instead, RangeVarGetRelid, RuleStmt::relation, RuleStmt::replace, RuleStmt::rulename, and transformRuleStmt().
Referenced by ProcessUtilitySlow().
{
List *actions;
Node *whereClause;
Oid relId;
/* Parse analysis. */
transformRuleStmt(stmt, queryString, &actions, &whereClause);
/*
* Find and lock the relation. Lock level should match
* DefineQueryRewrite.
*/
relId = RangeVarGetRelid(stmt->relation, AccessExclusiveLock, false);
/* ... and execute */
return DefineQueryRewrite(stmt->rulename,
relId,
whereClause,
stmt->event,
stmt->instead,
stmt->replace,
actions);
}
| void EnableDisableRule | ( | Relation | rel, | |
| const char * | rulename, | |||
| char | fires_when | |||
| ) |
Definition at line 771 of file rewriteDefine.c.
References ACL_KIND_CLASS, aclcheck_error(), ACLCHECK_NOT_OWNER, Assert, CacheInvalidateRelcache(), CatalogUpdateIndexes(), CharGetDatum, DatumGetChar, ereport, errcode(), errmsg(), ERROR, get_rel_name(), GETSTRUCT, GetUserId(), heap_close, heap_freetuple(), heap_open(), HeapTupleGetOid, HeapTupleIsValid, InvokeObjectPostAlterHook, ObjectIdGetDatum, pg_class_ownercheck(), PointerGetDatum, RelationGetRelid, RewriteRelationId, RowExclusiveLock, RULERELNAME, SearchSysCacheCopy2, simple_heap_update(), and HeapTupleData::t_self.
Referenced by ATExecEnableDisableRule().
{
Relation pg_rewrite_desc;
Oid owningRel = RelationGetRelid(rel);
Oid eventRelationOid;
HeapTuple ruletup;
bool changed = false;
/*
* Find the rule tuple to change.
*/
pg_rewrite_desc = heap_open(RewriteRelationId, RowExclusiveLock);
ruletup = SearchSysCacheCopy2(RULERELNAME,
ObjectIdGetDatum(owningRel),
PointerGetDatum(rulename));
if (!HeapTupleIsValid(ruletup))
ereport(ERROR,
(errcode(ERRCODE_UNDEFINED_OBJECT),
errmsg("rule \"%s\" for relation \"%s\" does not exist",
rulename, get_rel_name(owningRel))));
/*
* Verify that the user has appropriate permissions.
*/
eventRelationOid = ((Form_pg_rewrite) GETSTRUCT(ruletup))->ev_class;
Assert(eventRelationOid == owningRel);
if (!pg_class_ownercheck(eventRelationOid, GetUserId()))
aclcheck_error(ACLCHECK_NOT_OWNER, ACL_KIND_CLASS,
get_rel_name(eventRelationOid));
/*
* Change ev_enabled if it is different from the desired new state.
*/
if (DatumGetChar(((Form_pg_rewrite) GETSTRUCT(ruletup))->ev_enabled) !=
fires_when)
{
((Form_pg_rewrite) GETSTRUCT(ruletup))->ev_enabled =
CharGetDatum(fires_when);
simple_heap_update(pg_rewrite_desc, &ruletup->t_self, ruletup);
/* keep system catalog indexes current */
CatalogUpdateIndexes(pg_rewrite_desc, ruletup);
changed = true;
}
InvokeObjectPostAlterHook(RewriteRelationId,
HeapTupleGetOid(ruletup), 0);
heap_freetuple(ruletup);
heap_close(pg_rewrite_desc, RowExclusiveLock);
/*
* If we changed anything, broadcast a SI inval message to force each
* backend (including our own!) to rebuild relation's relcache entry.
* Otherwise they will fail to apply the change promptly.
*/
if (changed)
CacheInvalidateRelcache(rel);
}
Definition at line 872 of file rewriteDefine.c.
References AccessExclusiveLock, CacheInvalidateRelcache(), CatalogUpdateIndexes(), CMD_SELECT, ereport, errcode(), errmsg(), ERROR, GETSTRUCT, heap_close, heap_freetuple(), heap_open(), HeapTupleGetOid, HeapTupleIsValid, IsDefinedRewriteRule(), namestrcpy(), NoLock, NULL, ObjectIdGetDatum, PointerGetDatum, RangeVarCallbackForRenameRule(), RangeVarGetRelidExtended(), relation_close(), relation_open(), RelationGetRelationName, RewriteRelationId, RowExclusiveLock, RULERELNAME, SearchSysCacheCopy2, simple_heap_update(), and HeapTupleData::t_self.
Referenced by ExecRenameStmt().
{
Oid relid;
Relation targetrel;
Relation pg_rewrite_desc;
HeapTuple ruletup;
Form_pg_rewrite ruleform;
Oid ruleOid;
/*
* Look up name, check permissions, and acquire lock (which we will NOT
* release until end of transaction).
*/
relid = RangeVarGetRelidExtended(relation, AccessExclusiveLock,
false, false,
RangeVarCallbackForRenameRule,
NULL);
/* Have lock already, so just need to build relcache entry. */
targetrel = relation_open(relid, NoLock);
/* Prepare to modify pg_rewrite */
pg_rewrite_desc = heap_open(RewriteRelationId, RowExclusiveLock);
/* Fetch the rule's entry (it had better exist) */
ruletup = SearchSysCacheCopy2(RULERELNAME,
ObjectIdGetDatum(relid),
PointerGetDatum(oldName));
if (!HeapTupleIsValid(ruletup))
ereport(ERROR,
(errcode(ERRCODE_UNDEFINED_OBJECT),
errmsg("rule \"%s\" for relation \"%s\" does not exist",
oldName, RelationGetRelationName(targetrel))));
ruleform = (Form_pg_rewrite) GETSTRUCT(ruletup);
ruleOid = HeapTupleGetOid(ruletup);
/* rule with the new name should not already exist */
if (IsDefinedRewriteRule(relid, newName))
ereport(ERROR,
(errcode(ERRCODE_DUPLICATE_OBJECT),
errmsg("rule \"%s\" for relation \"%s\" already exists",
newName, RelationGetRelationName(targetrel))));
/*
* We disallow renaming ON SELECT rules, because they should always be
* named "_RETURN".
*/
if (ruleform->ev_type == CMD_SELECT + '0')
ereport(ERROR,
(errcode(ERRCODE_INVALID_OBJECT_DEFINITION),
errmsg("renaming an ON SELECT rule is not allowed")));
/* OK, do the update */
namestrcpy(&(ruleform->rulename), newName);
simple_heap_update(pg_rewrite_desc, &ruletup->t_self, ruletup);
/* keep system catalog indexes current */
CatalogUpdateIndexes(pg_rewrite_desc, ruletup);
heap_freetuple(ruletup);
heap_close(pg_rewrite_desc, RowExclusiveLock);
/*
* Invalidate relation's relcache entry so that other backends (and this
* one too!) are sent SI message to make them rebuild relcache entries.
* (Ideally this should happen automatically...)
*/
CacheInvalidateRelcache(targetrel);
/*
* Close rel, but keep exclusive lock!
*/
relation_close(targetrel, NoLock);
return ruleOid;
}
Definition at line 714 of file rewriteDefine.c.
References setRuleCheckAsUser_walker().
Referenced by RelationBuildRuleLock().
{
(void) setRuleCheckAsUser_walker(node, &userid);
}
1.7.1