mirror of https://github.com/postgres/postgres
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bc61878682
commit
54d6706ded
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/*-------------------------------------------------------------------------
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* |
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* rewriteDefine.c |
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* routines for defining a rewrite rule |
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* |
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* Portions Copyright (c) 1996-2013, PostgreSQL Global Development Group |
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* Portions Copyright (c) 1994, Regents of the University of California |
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* |
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* |
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* IDENTIFICATION |
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* src/backend/rewrite/rewriteDefine.c |
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* |
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*------------------------------------------------------------------------- |
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*/ |
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#include "postgres.h" |
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#include "access/heapam.h" |
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#include "access/htup_details.h" |
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#include "access/multixact.h" |
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#include "access/transam.h" |
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#include "access/xact.h" |
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#include "catalog/catalog.h" |
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#include "catalog/dependency.h" |
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#include "catalog/heap.h" |
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#include "catalog/indexing.h" |
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#include "catalog/namespace.h" |
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#include "catalog/objectaccess.h" |
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#include "catalog/pg_rewrite.h" |
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#include "catalog/storage.h" |
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#include "miscadmin.h" |
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#include "nodes/nodeFuncs.h" |
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#include "parser/parse_utilcmd.h" |
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#include "rewrite/rewriteDefine.h" |
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#include "rewrite/rewriteManip.h" |
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#include "rewrite/rewriteSupport.h" |
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#include "utils/acl.h" |
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#include "utils/builtins.h" |
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#include "utils/inval.h" |
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#include "utils/lsyscache.h" |
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#include "utils/rel.h" |
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#include "utils/syscache.h" |
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#include "utils/tqual.h" |
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static void checkRuleResultList(List *targetList, TupleDesc resultDesc, |
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bool isSelect); |
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static bool setRuleCheckAsUser_walker(Node *node, Oid *context); |
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static void setRuleCheckAsUser_Query(Query *qry, Oid userid); |
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/*
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* InsertRule - |
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* takes the arguments and inserts them as a row into the system |
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* relation "pg_rewrite" |
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*/ |
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static Oid |
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InsertRule(char *rulname, |
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int evtype, |
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Oid eventrel_oid, |
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AttrNumber evslot_index, |
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bool evinstead, |
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Node *event_qual, |
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List *action, |
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bool replace) |
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{ |
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char *evqual = nodeToString(event_qual); |
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char *actiontree = nodeToString((Node *) action); |
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Datum values[Natts_pg_rewrite]; |
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bool nulls[Natts_pg_rewrite]; |
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bool replaces[Natts_pg_rewrite]; |
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NameData rname; |
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Relation pg_rewrite_desc; |
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HeapTuple tup, |
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oldtup; |
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Oid rewriteObjectId; |
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ObjectAddress myself, |
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referenced; |
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bool is_update = false; |
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/*
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* Set up *nulls and *values arrays |
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*/ |
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MemSet(nulls, false, sizeof(nulls)); |
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namestrcpy(&rname, rulname); |
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values[Anum_pg_rewrite_rulename - 1] = NameGetDatum(&rname); |
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values[Anum_pg_rewrite_ev_class - 1] = ObjectIdGetDatum(eventrel_oid); |
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values[Anum_pg_rewrite_ev_attr - 1] = Int16GetDatum(evslot_index); |
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values[Anum_pg_rewrite_ev_type - 1] = CharGetDatum(evtype + '0'); |
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values[Anum_pg_rewrite_ev_enabled - 1] = CharGetDatum(RULE_FIRES_ON_ORIGIN); |
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values[Anum_pg_rewrite_is_instead - 1] = BoolGetDatum(evinstead); |
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values[Anum_pg_rewrite_ev_qual - 1] = CStringGetTextDatum(evqual); |
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values[Anum_pg_rewrite_ev_action - 1] = CStringGetTextDatum(actiontree); |
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/*
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* Ready to store new pg_rewrite tuple |
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*/ |
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pg_rewrite_desc = heap_open(RewriteRelationId, RowExclusiveLock); |
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/*
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* Check to see if we are replacing an existing tuple |
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*/ |
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oldtup = SearchSysCache2(RULERELNAME, |
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ObjectIdGetDatum(eventrel_oid), |
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PointerGetDatum(rulname)); |
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if (HeapTupleIsValid(oldtup)) |
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{ |
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if (!replace) |
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ereport(ERROR, |
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(errcode(ERRCODE_DUPLICATE_OBJECT), |
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errmsg("rule \"%s\" for relation \"%s\" already exists", |
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rulname, get_rel_name(eventrel_oid)))); |
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/*
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* When replacing, we don't need to replace every attribute |
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*/ |
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MemSet(replaces, false, sizeof(replaces)); |
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replaces[Anum_pg_rewrite_ev_attr - 1] = true; |
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replaces[Anum_pg_rewrite_ev_type - 1] = true; |
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replaces[Anum_pg_rewrite_is_instead - 1] = true; |
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replaces[Anum_pg_rewrite_ev_qual - 1] = true; |
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replaces[Anum_pg_rewrite_ev_action - 1] = true; |
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tup = heap_modify_tuple(oldtup, RelationGetDescr(pg_rewrite_desc), |
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values, nulls, replaces); |
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simple_heap_update(pg_rewrite_desc, &tup->t_self, tup); |
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ReleaseSysCache(oldtup); |
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rewriteObjectId = HeapTupleGetOid(tup); |
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is_update = true; |
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} |
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else |
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{ |
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tup = heap_form_tuple(pg_rewrite_desc->rd_att, values, nulls); |
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rewriteObjectId = simple_heap_insert(pg_rewrite_desc, tup); |
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} |
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/* Need to update indexes in either case */ |
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CatalogUpdateIndexes(pg_rewrite_desc, tup); |
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heap_freetuple(tup); |
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/* If replacing, get rid of old dependencies and make new ones */ |
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if (is_update) |
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deleteDependencyRecordsFor(RewriteRelationId, rewriteObjectId, false); |
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/*
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* Install dependency on rule's relation to ensure it will go away on |
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* relation deletion. If the rule is ON SELECT, make the dependency |
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* implicit --- this prevents deleting a view's SELECT rule. Other kinds |
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* of rules can be AUTO. |
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*/ |
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myself.classId = RewriteRelationId; |
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myself.objectId = rewriteObjectId; |
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myself.objectSubId = 0; |
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referenced.classId = RelationRelationId; |
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referenced.objectId = eventrel_oid; |
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referenced.objectSubId = 0; |
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recordDependencyOn(&myself, &referenced, |
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(evtype == CMD_SELECT) ? DEPENDENCY_INTERNAL : DEPENDENCY_AUTO); |
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/*
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* Also install dependencies on objects referenced in action and qual. |
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*/ |
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recordDependencyOnExpr(&myself, (Node *) action, NIL, |
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DEPENDENCY_NORMAL); |
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if (event_qual != NULL) |
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{ |
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/* Find query containing OLD/NEW rtable entries */ |
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Query *qry = (Query *) linitial(action); |
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qry = getInsertSelectQuery(qry, NULL); |
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recordDependencyOnExpr(&myself, event_qual, qry->rtable, |
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DEPENDENCY_NORMAL); |
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} |
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/* Post creation hook for new rule */ |
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InvokeObjectAccessHook(OAT_POST_CREATE, |
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RewriteRelationId, rewriteObjectId, 0, NULL); |
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heap_close(pg_rewrite_desc, RowExclusiveLock); |
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return rewriteObjectId; |
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} |
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/*
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* DefineRule |
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* Execute a CREATE RULE command. |
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*/ |
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Oid |
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DefineRule(RuleStmt *stmt, const char *queryString) |
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{ |
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List *actions; |
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Node *whereClause; |
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Oid relId; |
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/* Parse analysis. */ |
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transformRuleStmt(stmt, queryString, &actions, &whereClause); |
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/*
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* Find and lock the relation. Lock level should match |
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* DefineQueryRewrite. |
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*/ |
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relId = RangeVarGetRelid(stmt->relation, AccessExclusiveLock, false); |
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/* ... and execute */ |
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return DefineQueryRewrite(stmt->rulename, |
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relId, |
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whereClause, |
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stmt->event, |
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stmt->instead, |
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stmt->replace, |
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actions); |
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} |
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/*
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* DefineQueryRewrite |
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* Create a rule |
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* |
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* This is essentially the same as DefineRule() except that the rule's |
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* action and qual have already been passed through parse analysis. |
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*/ |
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Oid |
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DefineQueryRewrite(char *rulename, |
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Oid event_relid, |
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Node *event_qual, |
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CmdType event_type, |
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bool is_instead, |
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bool replace, |
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List *action) |
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{ |
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Relation event_relation; |
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int event_attno; |
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ListCell *l; |
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Query *query; |
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bool RelisBecomingView = false; |
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Oid ruleId = InvalidOid; |
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/*
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* If we are installing an ON SELECT rule, we had better grab |
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* AccessExclusiveLock to ensure no SELECTs are currently running on the |
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* event relation. For other types of rules, it would be sufficient to |
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* grab ShareRowExclusiveLock to lock out insert/update/delete actions and |
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* to ensure that we lock out current CREATE RULE statements; but because |
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* of race conditions in access to catalog entries, we can't do that yet. |
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* |
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* Note that this lock level should match the one used in DefineRule. |
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*/ |
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event_relation = heap_open(event_relid, AccessExclusiveLock); |
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/*
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* Verify relation is of a type that rules can sensibly be applied to. |
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*/ |
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if (event_relation->rd_rel->relkind != RELKIND_RELATION && |
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event_relation->rd_rel->relkind != RELKIND_VIEW) |
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ereport(ERROR, |
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(errcode(ERRCODE_WRONG_OBJECT_TYPE), |
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errmsg("\"%s\" is not a table or view", |
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RelationGetRelationName(event_relation)))); |
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if (!allowSystemTableMods && IsSystemRelation(event_relation)) |
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ereport(ERROR, |
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(errcode(ERRCODE_INSUFFICIENT_PRIVILEGE), |
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errmsg("permission denied: \"%s\" is a system catalog", |
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RelationGetRelationName(event_relation)))); |
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/*
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* Check user has permission to apply rules to this relation. |
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*/ |
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if (!pg_class_ownercheck(event_relid, GetUserId())) |
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aclcheck_error(ACLCHECK_NOT_OWNER, ACL_KIND_CLASS, |
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RelationGetRelationName(event_relation)); |
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/*
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* No rule actions that modify OLD or NEW |
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*/ |
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foreach(l, action) |
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{ |
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query = (Query *) lfirst(l); |
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if (query->resultRelation == 0) |
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continue; |
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/* Don't be fooled by INSERT/SELECT */ |
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if (query != getInsertSelectQuery(query, NULL)) |
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continue; |
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if (query->resultRelation == PRS2_OLD_VARNO) |
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ereport(ERROR, |
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(errcode(ERRCODE_FEATURE_NOT_SUPPORTED), |
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errmsg("rule actions on OLD are not implemented"), |
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errhint("Use views or triggers instead."))); |
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if (query->resultRelation == PRS2_NEW_VARNO) |
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ereport(ERROR, |
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(errcode(ERRCODE_FEATURE_NOT_SUPPORTED), |
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errmsg("rule actions on NEW are not implemented"), |
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errhint("Use triggers instead."))); |
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} |
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if (event_type == CMD_SELECT) |
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{ |
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/*
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* Rules ON SELECT are restricted to view definitions |
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* |
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* So there cannot be INSTEAD NOTHING, ... |
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*/ |
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if (list_length(action) == 0) |
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ereport(ERROR, |
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(errcode(ERRCODE_FEATURE_NOT_SUPPORTED), |
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errmsg("INSTEAD NOTHING rules on SELECT are not implemented"), |
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errhint("Use views instead."))); |
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/*
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* ... there cannot be multiple actions, ... |
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*/ |
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if (list_length(action) > 1) |
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ereport(ERROR, |
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(errcode(ERRCODE_FEATURE_NOT_SUPPORTED), |
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errmsg("multiple actions for rules on SELECT are not implemented"))); |
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/*
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* ... the one action must be a SELECT, ... |
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*/ |
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query = (Query *) linitial(action); |
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if (!is_instead || |
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query->commandType != CMD_SELECT || |
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query->utilityStmt != NULL) |
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ereport(ERROR, |
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(errcode(ERRCODE_FEATURE_NOT_SUPPORTED), |
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errmsg("rules on SELECT must have action INSTEAD SELECT"))); |
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/*
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* ... it cannot contain data-modifying WITH ... |
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*/ |
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if (query->hasModifyingCTE) |
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ereport(ERROR, |
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(errcode(ERRCODE_FEATURE_NOT_SUPPORTED), |
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errmsg("rules on SELECT must not contain data-modifying statements in WITH"))); |
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/*
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* ... there can be no rule qual, ... |
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*/ |
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if (event_qual != NULL) |
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ereport(ERROR, |
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(errcode(ERRCODE_FEATURE_NOT_SUPPORTED), |
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errmsg("event qualifications are not implemented for rules on SELECT"))); |
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/*
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* ... the targetlist of the SELECT action must exactly match the |
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* event relation, ... |
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*/ |
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checkRuleResultList(query->targetList, |
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RelationGetDescr(event_relation), |
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true); |
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/*
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* ... there must not be another ON SELECT rule already ... |
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*/ |
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if (!replace && event_relation->rd_rules != NULL) |
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{ |
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int i; |
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for (i = 0; i < event_relation->rd_rules->numLocks; i++) |
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{ |
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RewriteRule *rule; |
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rule = event_relation->rd_rules->rules[i]; |
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if (rule->event == CMD_SELECT) |
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ereport(ERROR, |
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(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE), |
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errmsg("\"%s\" is already a view", |
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RelationGetRelationName(event_relation)))); |
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} |
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} |
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/*
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* ... and finally the rule must be named _RETURN. |
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*/ |
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if (strcmp(rulename, ViewSelectRuleName) != 0) |
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{ |
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/*
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* In versions before 7.3, the expected name was _RETviewname. For |
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* backwards compatibility with old pg_dump output, accept that |
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* and silently change it to _RETURN. Since this is just a quick |
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* backwards-compatibility hack, limit the number of characters |
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* checked to a few less than NAMEDATALEN; this saves having to |
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* worry about where a multibyte character might have gotten |
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* truncated. |
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*/ |
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if (strncmp(rulename, "_RET", 4) != 0 || |
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strncmp(rulename + 4, RelationGetRelationName(event_relation), |
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NAMEDATALEN - 4 - 4) != 0) |
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ereport(ERROR, |
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(errcode(ERRCODE_INVALID_OBJECT_DEFINITION), |
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errmsg("view rule for \"%s\" must be named \"%s\"", |
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RelationGetRelationName(event_relation), |
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ViewSelectRuleName))); |
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rulename = pstrdup(ViewSelectRuleName); |
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} |
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/*
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* Are we converting a relation to a view? |
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* |
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* If so, check that the relation is empty because the storage for the |
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* relation is going to be deleted. Also insist that the rel not have |
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* any triggers, indexes, or child tables. (Note: these tests are too |
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* strict, because they will reject relations that once had such but |
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* don't anymore. But we don't really care, because this whole |
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* business of converting relations to views is just a kluge to allow |
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* dump/reload of views that participate in circular dependencies.) |
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*/ |
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if (event_relation->rd_rel->relkind != RELKIND_VIEW) |
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{ |
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HeapScanDesc scanDesc; |
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scanDesc = heap_beginscan(event_relation, SnapshotNow, 0, NULL); |
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if (heap_getnext(scanDesc, ForwardScanDirection) != NULL) |
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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; |
|
||||||
} |
|
||||||
|
|
||||||
/*
|
|
||||||
* checkRuleResultList |
|
||||||
* Verify that targetList produces output compatible with a tupledesc |
|
||||||
* |
|
||||||
* The targetList might be either a SELECT targetlist, or a RETURNING list; |
|
||||||
* isSelect tells which. (This is mostly used for choosing error messages, |
|
||||||
* but also we don't enforce column name matching for RETURNING.) |
|
||||||
*/ |
|
||||||
static void |
|
||||||
checkRuleResultList(List *targetList, TupleDesc resultDesc, bool isSelect) |
|
||||||
{ |
|
||||||
ListCell *tllist; |
|
||||||
int i; |
|
||||||
|
|
||||||
i = 0; |
|
||||||
foreach(tllist, targetList) |
|
||||||
{ |
|
||||||
TargetEntry *tle = (TargetEntry *) lfirst(tllist); |
|
||||||
int32 tletypmod; |
|
||||||
Form_pg_attribute attr; |
|
||||||
char *attname; |
|
||||||
|
|
||||||
/* resjunk entries may be ignored */ |
|
||||||
if (tle->resjunk) |
|
||||||
continue; |
|
||||||
i++; |
|
||||||
if (i > resultDesc->natts) |
|
||||||
ereport(ERROR, |
|
||||||
(errcode(ERRCODE_INVALID_OBJECT_DEFINITION), |
|
||||||
isSelect ? |
|
||||||
errmsg("SELECT rule's target list has too many entries") : |
|
||||||
errmsg("RETURNING list has too many entries"))); |
|
||||||
|
|
||||||
attr = resultDesc->attrs[i - 1]; |
|
||||||
attname = NameStr(attr->attname); |
|
||||||
|
|
||||||
/*
|
|
||||||
* Disallow dropped columns in the relation. This won't happen in the |
|
||||||
* cases we actually care about (namely creating a view via CREATE |
|
||||||
* TABLE then CREATE RULE, or adding a RETURNING rule to a view). |
|
||||||
* Trying to cope with it is much more trouble than it's worth, |
|
||||||
* because we'd have to modify the rule to insert dummy NULLs at the |
|
||||||
* right positions. |
|
||||||
*/ |
|
||||||
if (attr->attisdropped) |
|
||||||
ereport(ERROR, |
|
||||||
(errcode(ERRCODE_FEATURE_NOT_SUPPORTED), |
|
||||||
errmsg("cannot convert relation containing dropped columns to view"))); |
|
||||||
|
|
||||||
if (isSelect && strcmp(tle->resname, attname) != 0) |
|
||||||
ereport(ERROR, |
|
||||||
(errcode(ERRCODE_INVALID_OBJECT_DEFINITION), |
|
||||||
errmsg("SELECT rule's target entry %d has different column name from \"%s\"", i, attname))); |
|
||||||
|
|
||||||
if (attr->atttypid != exprType((Node *) tle->expr)) |
|
||||||
ereport(ERROR, |
|
||||||
(errcode(ERRCODE_INVALID_OBJECT_DEFINITION), |
|
||||||
isSelect ? |
|
||||||
errmsg("SELECT rule's target entry %d has different type from column \"%s\"", |
|
||||||
i, attname) : |
|
||||||
errmsg("RETURNING list's entry %d has different type from column \"%s\"", |
|
||||||
i, attname))); |
|
||||||
|
|
||||||
/*
|
|
||||||
* Allow typmods to be different only if one of them is -1, ie, |
|
||||||
* "unspecified". This is necessary for cases like "numeric", where |
|
||||||
* the table will have a filled-in default length but the select |
|
||||||
* rule's expression will probably have typmod = -1. |
|
||||||
*/ |
|
||||||
tletypmod = exprTypmod((Node *) tle->expr); |
|
||||||
if (attr->atttypmod != tletypmod && |
|
||||||
attr->atttypmod != -1 && tletypmod != -1) |
|
||||||
ereport(ERROR, |
|
||||||
(errcode(ERRCODE_INVALID_OBJECT_DEFINITION), |
|
||||||
isSelect ? |
|
||||||
errmsg("SELECT rule's target entry %d has different size from column \"%s\"", |
|
||||||
i, attname) : |
|
||||||
errmsg("RETURNING list's entry %d has different size from column \"%s\"", |
|
||||||
i, attname))); |
|
||||||
} |
|
||||||
|
|
||||||
if (i != resultDesc->natts) |
|
||||||
ereport(ERROR, |
|
||||||
(errcode(ERRCODE_INVALID_OBJECT_DEFINITION), |
|
||||||
isSelect ? |
|
||||||
errmsg("SELECT rule's target list has too few entries") : |
|
||||||
errmsg("RETURNING list has too few entries"))); |
|
||||||
} |
|
||||||
|
|
||||||
/*
|
|
||||||
* setRuleCheckAsUser |
|
||||||
* Recursively scan a query or expression tree and set the checkAsUser |
|
||||||
* field to the given userid in all rtable entries. |
|
||||||
* |
|
||||||
* Note: for a view (ON SELECT rule), the checkAsUser field of the OLD |
|
||||||
* RTE entry will be overridden when the view rule is expanded, and the |
|
||||||
* checkAsUser field of the NEW entry is irrelevant because that entry's |
|
||||||
* requiredPerms bits will always be zero. However, for other types of rules |
|
||||||
* it's important to set these fields to match the rule owner. So we just set |
|
||||||
* them always. |
|
||||||
*/ |
|
||||||
void |
|
||||||
setRuleCheckAsUser(Node *node, Oid userid) |
|
||||||
{ |
|
||||||
(void) setRuleCheckAsUser_walker(node, &userid); |
|
||||||
} |
|
||||||
|
|
||||||
static bool |
|
||||||
setRuleCheckAsUser_walker(Node *node, Oid *context) |
|
||||||
{ |
|
||||||
if (node == NULL) |
|
||||||
return false; |
|
||||||
if (IsA(node, Query)) |
|
||||||
{ |
|
||||||
setRuleCheckAsUser_Query((Query *) node, *context); |
|
||||||
return false; |
|
||||||
} |
|
||||||
return expression_tree_walker(node, setRuleCheckAsUser_walker, |
|
||||||
(void *) context); |
|
||||||
} |
|
||||||
|
|
||||||
static void |
|
||||||
setRuleCheckAsUser_Query(Query *qry, Oid userid) |
|
||||||
{ |
|
||||||
ListCell *l; |
|
||||||
|
|
||||||
/* Set all the RTEs in this query node */ |
|
||||||
foreach(l, qry->rtable) |
|
||||||
{ |
|
||||||
RangeTblEntry *rte = (RangeTblEntry *) lfirst(l); |
|
||||||
|
|
||||||
if (rte->rtekind == RTE_SUBQUERY) |
|
||||||
{ |
|
||||||
/* Recurse into subquery in FROM */ |
|
||||||
setRuleCheckAsUser_Query(rte->subquery, userid); |
|
||||||
} |
|
||||||
else |
|
||||||
rte->checkAsUser = userid; |
|
||||||
} |
|
||||||
|
|
||||||
/* Recurse into subquery-in-WITH */ |
|
||||||
foreach(l, qry->cteList) |
|
||||||
{ |
|
||||||
CommonTableExpr *cte = (CommonTableExpr *) lfirst(l); |
|
||||||
|
|
||||||
setRuleCheckAsUser_Query((Query *) cte->ctequery, userid); |
|
||||||
} |
|
||||||
|
|
||||||
/* If there are sublinks, search for them and process their RTEs */ |
|
||||||
if (qry->hasSubLinks) |
|
||||||
query_tree_walker(qry, setRuleCheckAsUser_walker, (void *) &userid, |
|
||||||
QTW_IGNORE_RC_SUBQUERIES); |
|
||||||
} |
|
||||||
|
|
||||||
|
|
||||||
/*
|
|
||||||
* Change the firing semantics of an existing rule. |
|
||||||
*/ |
|
||||||
void |
|
||||||
EnableDisableRule(Relation rel, const char *rulename, |
|
||||||
char fires_when) |
|
||||||
{ |
|
||||||
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; |
|
||||||
} |
|
||||||
|
|
||||||
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); |
|
||||||
} |
|
||||||
|
|
||||||
|
|
||||||
/*
|
|
||||||
* Perform permissions and integrity checks before acquiring a relation lock. |
|
||||||
*/ |
|
||||||
static void |
|
||||||
RangeVarCallbackForRenameRule(const RangeVar *rv, Oid relid, Oid oldrelid, |
|
||||||
void *arg) |
|
||||||
{ |
|
||||||
HeapTuple tuple; |
|
||||||
Form_pg_class form; |
|
||||||
|
|
||||||
tuple = SearchSysCache1(RELOID, ObjectIdGetDatum(relid)); |
|
||||||
if (!HeapTupleIsValid(tuple)) |
|
||||||
return; /* concurrently dropped */ |
|
||||||
form = (Form_pg_class) GETSTRUCT(tuple); |
|
||||||
|
|
||||||
/* only tables and views can have rules */ |
|
||||||
if (form->relkind != RELKIND_RELATION && form->relkind != RELKIND_VIEW) |
|
||||||
ereport(ERROR, |
|
||||||
(errcode(ERRCODE_WRONG_OBJECT_TYPE), |
|
||||||
errmsg("\"%s\" is not a table or view", rv->relname))); |
|
||||||
|
|
||||||
if (!allowSystemTableMods && IsSystemClass(form)) |
|
||||||
ereport(ERROR, |
|
||||||
(errcode(ERRCODE_INSUFFICIENT_PRIVILEGE), |
|
||||||
errmsg("permission denied: \"%s\" is a system catalog", |
|
||||||
rv->relname))); |
|
||||||
|
|
||||||
/* you must own the table to rename one of its rules */ |
|
||||||
if (!pg_class_ownercheck(relid, GetUserId())) |
|
||||||
aclcheck_error(ACLCHECK_NOT_OWNER, ACL_KIND_CLASS, rv->relname); |
|
||||||
|
|
||||||
ReleaseSysCache(tuple); |
|
||||||
} |
|
||||||
|
|
||||||
/*
|
|
||||||
* Rename an existing rewrite rule. |
|
||||||
*/ |
|
||||||
Oid |
|
||||||
RenameRewriteRule(RangeVar *relation, const char *oldName, |
|
||||||
const char *newName) |
|
||||||
{ |
|
||||||
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; |
|
||||||
} |
|
Loading…
Reference in new issue