Add code to extract dependencies from an expression tree, and use it

to build dependencies for rules, constraint expressions, and default
expressions.  Repair some problems in the original design of
recursiveDeletion() exposed by more complex dependency sets.  Fix
regression tests that were deleting things in illegal sequences.

Author: tglsfdc

src/backend/catalog/dependency.c

@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *	  $Header: /cvsroot/pgsql/src/backend/catalog/heap.c,v 1.207 2002/07/15 16:33:31 tgl Exp $
+ *	  $Header: /cvsroot/pgsql/src/backend/catalog/heap.c,v 1.208 2002/07/16 05:53:33 tgl Exp $
  *
  *
  * INTERFACE ROUTINES
@@ -1157,10 +1157,15 @@ StoreAttrDefault(Relation rel, AttrNumber attnum, char *adbin)
 	colobject.objectSubId = attnum;
 
 	recordDependencyOn(&defobject, &colobject, DEPENDENCY_AUTO);
+
+	/*
+	 * Record dependencies on objects used in the expression, too.
+	 */
+	recordDependencyOnExpr(&defobject, expr, NIL, DEPENDENCY_NORMAL);
 }
 
 /*
- * Store a constraint expression for the given relation.
+ * Store a check-constraint expression for the given relation.
  * The expression must be presented as a nodeToString() string.
  *
  * Caller is responsible for updating the count of constraints
@@ -1191,6 +1196,10 @@ StoreRelCheck(Relation rel, char *ccname, char *ccbin)
 
 	/*
 	 * Find columns of rel that are used in ccbin
+	 *
+	 * NB: pull_var_clause is okay here only because we don't allow
+	 * subselects in check constraints; it would fail to examine the
+	 * contents of subselects.
 	 */
 	varList = pull_var_clause(expr, false);
 	keycount = length(varList);
@@ -1226,15 +1235,16 @@ StoreRelCheck(Relation rel, char *ccname, char *ccbin)
 						  false, 	/* Is Deferrable */
 						  false,	/* Is Deferred */
 						  RelationGetRelid(rel), /* relation */
-						  attNos,	/* List of attributes in the constraint */
-						  keycount,	/* # attributes in the constraint */
+						  attNos,	/* attrs in the constraint */
+						  keycount,	/* # attrs in the constraint */
 						  InvalidOid, /* not a domain constraint */
 						  InvalidOid, /* Foreign key fields */
 						  NULL,
 						  0,
 						  ' ',
 						  ' ',
 						  ' ',
+						  expr,		/* Tree form check constraint */
 						  ccbin,	/* Binary form check constraint */
 						  ccsrc);	/* Source form check constraint */
 

src/backend/catalog/heap.c

@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *	  $Header: /cvsroot/pgsql/src/backend/catalog/index.c,v 1.183 2002/07/14 21:08:08 tgl Exp $
+ *	  $Header: /cvsroot/pgsql/src/backend/catalog/index.c,v 1.184 2002/07/16 05:53:33 tgl Exp $
  *
  *
  * INTERFACE ROUTINES
@@ -712,7 +712,8 @@ index_create(Oid heapRelationId,
 										   ' ',
 										   ' ',
 										   ' ',
-										   NULL, /* Constraint Bin & Src */
+										   NULL, /* no check constraint */
+										   NULL,
 										   NULL);
 
 			referenced.classId = get_system_catalog_relid(ConstraintRelationName);

src/backend/catalog/index.c

@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *	  $Header: /cvsroot/pgsql/src/backend/catalog/pg_constraint.c,v 1.1 2002/07/12 18:43:15 tgl Exp $
+ *	  $Header: /cvsroot/pgsql/src/backend/catalog/pg_constraint.c,v 1.2 2002/07/16 05:53:33 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -52,6 +52,7 @@ CreateConstraintEntry(const char *constraintName,
 					  char foreignUpdateType,
 					  char foreignDeleteType,
 					  char foreignMatchType,
+					  Node *conExpr,
 					  const char *conBin,
 					  const char *conSrc)
 {
@@ -227,6 +228,24 @@ CreateConstraintEntry(const char *constraintName,
 		}
 	}
 
+	if (conExpr != NULL)
+	{
+		/*
+		 * Register dependencies from constraint to objects mentioned
+		 * in CHECK expression.  We gin up a rather bogus rangetable
+		 * list to handle any Vars in the constraint.
+		 */
+		RangeTblEntry	rte;
+
+		MemSet(&rte, 0, sizeof(rte));
+		rte.type = T_RangeTblEntry;
+		rte.rtekind = RTE_RELATION;
+		rte.relid = relId;
+
+		recordDependencyOnExpr(&conobject, conExpr, makeList1(&rte),
+							   DEPENDENCY_NORMAL);
+	}
+
 	return conOid;
 }
 

src/backend/catalog/pg_constraint.c

@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *	  $Header: /cvsroot/pgsql/src/backend/catalog/pg_depend.c,v 1.1 2002/07/12 18:43:15 tgl Exp $
+ *	  $Header: /cvsroot/pgsql/src/backend/catalog/pg_depend.c,v 1.2 2002/07/16 05:53:33 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -38,13 +38,30 @@ void
 recordDependencyOn(const ObjectAddress *depender,
 				   const ObjectAddress *referenced,
 				   DependencyType behavior)
+{
+	recordMultipleDependencies(depender, referenced, 1, behavior);
+}
+
+/*
+ * Record multiple dependencies (of the same kind) for a single dependent
+ * object.  This has a little less overhead than recording each separately.
+ */
+void
+recordMultipleDependencies(const ObjectAddress *depender,
+						   const ObjectAddress *referenced,
+						   int nreferenced,
+						   DependencyType behavior)
 {
 	Relation	dependDesc;
 	HeapTuple	tup;
 	int			i;
 	char		nulls[Natts_pg_depend];
 	Datum		values[Natts_pg_depend];
 	Relation	idescs[Num_pg_depend_indices];
+	bool		indices_opened = false;
+
+	if (nreferenced <= 0)
+		return;					/* nothing to do */
 
 	/*
 	 * During bootstrap, do nothing since pg_depend may not exist yet.
@@ -55,44 +72,51 @@ recordDependencyOn(const ObjectAddress *depender,
 
 	dependDesc = heap_openr(DependRelationName, RowExclusiveLock);
 
-	/*
-	 * If the referenced object is pinned by the system, there's no real
-	 * need to record dependencies on it.  This saves lots of space in
-	 * pg_depend, so it's worth the time taken to check.
-	 */
-	if (!isObjectPinned(referenced, dependDesc))
+	memset(nulls, ' ', sizeof(nulls));
+
+	for (i = 0; i < nreferenced; i++, referenced++)
 	{
 		/*
-		 * Record the Dependency.  Note we don't bother to check for
-		 * duplicate dependencies; there's no harm in them.
+		 * If the referenced object is pinned by the system, there's no real
+		 * need to record dependencies on it.  This saves lots of space in
+		 * pg_depend, so it's worth the time taken to check.
 		 */
-		for (i = 0; i < Natts_pg_depend; ++i)
+		if (!isObjectPinned(referenced, dependDesc))
 		{
-			nulls[i] = ' ';
-			values[i] = (Datum) 0;
+			/*
+			 * Record the Dependency.  Note we don't bother to check for
+			 * duplicate dependencies; there's no harm in them.
+			 */
+			values[Anum_pg_depend_classid - 1]	= ObjectIdGetDatum(depender->classId);
+			values[Anum_pg_depend_objid - 1]	= ObjectIdGetDatum(depender->objectId);
+			values[Anum_pg_depend_objsubid - 1]	= Int32GetDatum(depender->objectSubId);
+
+			values[Anum_pg_depend_refclassid - 1]	= ObjectIdGetDatum(referenced->classId);
+			values[Anum_pg_depend_refobjid - 1]		= ObjectIdGetDatum(referenced->objectId);
+			values[Anum_pg_depend_refobjsubid - 1]	= Int32GetDatum(referenced->objectSubId);
+
+			values[Anum_pg_depend_deptype -1] = CharGetDatum((char) behavior);
+
+			tup = heap_formtuple(dependDesc->rd_att, values, nulls);
+
+			simple_heap_insert(dependDesc, tup);
+
+			/*
+			 * Keep indices current
+			 */
+			if (!indices_opened)
+			{
+				CatalogOpenIndices(Num_pg_depend_indices, Name_pg_depend_indices, idescs);
+				indices_opened = true;
+			}
+			CatalogIndexInsert(idescs, Num_pg_depend_indices, dependDesc, tup);
+
+			heap_freetuple(tup);
 		}
+	}
 
-		values[Anum_pg_depend_classid - 1]	= ObjectIdGetDatum(depender->classId);
-		values[Anum_pg_depend_objid - 1]	= ObjectIdGetDatum(depender->objectId);
-		values[Anum_pg_depend_objsubid - 1]	= Int32GetDatum(depender->objectSubId);
-
-		values[Anum_pg_depend_refclassid - 1]	= ObjectIdGetDatum(referenced->classId);
-		values[Anum_pg_depend_refobjid - 1]		= ObjectIdGetDatum(referenced->objectId);
-		values[Anum_pg_depend_refobjsubid - 1]	= Int32GetDatum(referenced->objectSubId);
-
-		values[Anum_pg_depend_deptype -1] = CharGetDatum((char) behavior);
-
-		tup = heap_formtuple(dependDesc->rd_att, values, nulls);
-
-		simple_heap_insert(dependDesc, tup);
-
-		/*
-		 * Keep indices current
-		 */
-		CatalogOpenIndices(Num_pg_depend_indices, Name_pg_depend_indices, idescs);
-		CatalogIndexInsert(idescs, Num_pg_depend_indices, dependDesc, tup);
+	if (indices_opened)
 		CatalogCloseIndices(Num_pg_depend_indices, idescs);
-	}
 
 	heap_close(dependDesc, RowExclusiveLock);
 }

src/backend/catalog/pg_depend.c

@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *	  $Header: /cvsroot/pgsql/src/backend/commands/tablecmds.c,v 1.21 2002/07/15 16:33:31 tgl Exp $
+ *	  $Header: /cvsroot/pgsql/src/backend/commands/tablecmds.c,v 1.22 2002/07/16 05:53:33 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -2708,6 +2708,7 @@ createForeignKeyConstraint(Relation rel, Relation pkrel,
 								 fkconstraint->fk_upd_action,
 								 fkconstraint->fk_del_action,
 								 fkconstraint->fk_matchtype,
+								 NULL, /* no check constraint */
 								 NULL,
 								 NULL);
 }

src/backend/commands/tablecmds.c

@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *	  $Header: /cvsroot/pgsql/src/backend/rewrite/rewriteDefine.c,v 1.74 2002/07/12 18:43:17 tgl Exp $
+ *	  $Header: /cvsroot/pgsql/src/backend/rewrite/rewriteDefine.c,v 1.75 2002/07/16 05:53:34 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -47,9 +47,11 @@ InsertRule(char *rulname,
 		   Oid eventrel_oid,
 		   AttrNumber evslot_index,
 		   bool evinstead,
-		   char *evqual,
-		   char *actiontree)
+		   Node *event_qual,
+		   List *action)
 {
+	char	   *evqual = nodeToString(event_qual);
+	char	   *actiontree = nodeToString((Node *) action);
 	int			i;
 	Datum		values[Natts_pg_rewrite];
 	char		nulls[Natts_pg_rewrite];
@@ -123,6 +125,21 @@ InsertRule(char *rulname,
 	recordDependencyOn(&myself, &referenced,
 		(evtype == CMD_SELECT) ? DEPENDENCY_INTERNAL : DEPENDENCY_AUTO);
 
+	/*
+	 * Also install dependencies on objects referenced in action and qual.
+	 */
+	recordDependencyOnExpr(&myself, (Node *) action, NIL,
+						   DEPENDENCY_NORMAL);
+	if (event_qual != NULL)
+	{
+		/* Find query containing OLD/NEW rtable entries */
+		Query  *qry = (Query *) lfirst(action);
+
+		qry = getInsertSelectQuery(qry, NULL);
+		recordDependencyOnExpr(&myself, event_qual, qry->rtable,
+							   DEPENDENCY_NORMAL);
+	}
+
 	heap_close(pg_rewrite_desc, RowExclusiveLock);
 
 	return rewriteObjectId;
@@ -141,8 +158,6 @@ DefineQueryRewrite(RuleStmt *stmt)
 	Oid			ruleId;
 	int			event_attno;
 	Oid			event_attype;
-	char	   *actionP,
-			   *event_qualP;
 	List	   *l;
 	Query	   *query;
 	AclResult	aclresult;
@@ -342,16 +357,13 @@ DefineQueryRewrite(RuleStmt *stmt)
 	/* discard rule if it's null action and not INSTEAD; it's a no-op */
 	if (action != NIL || is_instead)
 	{
-		event_qualP = nodeToString(event_qual);
-		actionP = nodeToString(action);
-
 		ruleId = InsertRule(stmt->rulename,
 							event_type,
 							ev_relid,
 							event_attno,
 							is_instead,
-							event_qualP,
-							actionP);
+							event_qual,
+							action);
 
 		/*
 		 * Set pg_class 'relhasrules' field TRUE for event relation. If

src/backend/rewrite/rewriteDefine.c

@@ -7,7 +7,7 @@
  * Portions Copyright (c) 1996-2002, PostgreSQL Global Development Group
  * Portions Copyright (c) 1994, Regents of the University of California
  *
- * $Id: dependency.h,v 1.1 2002/07/12 18:43:19 tgl Exp $
+ * $Id: dependency.h,v 1.2 2002/07/16 05:53:34 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -83,10 +83,19 @@ typedef struct ObjectAddress
 extern void performDeletion(const ObjectAddress *object,
 							DropBehavior behavior);
 
+extern void recordDependencyOnExpr(const ObjectAddress *depender,
+								   Node *expr, List *rtable,
+								   DependencyType behavior);
+
 /* in pg_depend.c */
 
 extern void recordDependencyOn(const ObjectAddress *depender,
 							   const ObjectAddress *referenced,
 							   DependencyType behavior);
 
+extern void recordMultipleDependencies(const ObjectAddress *depender,
+									   const ObjectAddress *referenced,
+									   int nreferenced,
+									   DependencyType behavior);
+
 #endif   /* DEPENDENCY_H */

src/include/catalog/dependency.h

@@ -8,7 +8,7 @@
  * Portions Copyright (c) 1996-2002, PostgreSQL Global Development Group
  * Portions Copyright (c) 1994, Regents of the University of California
  *
- * $Id: pg_constraint.h,v 1.1 2002/07/12 18:43:19 tgl Exp $
+ * $Id: pg_constraint.h,v 1.2 2002/07/16 05:53:34 tgl Exp $
  *
  * NOTES
  *	  the genbki.sh script reads this file and generates .bki
@@ -158,6 +158,7 @@ extern Oid	CreateConstraintEntry(const char *constraintName,
 								  char foreignUpdateType,
 								  char foreignDeleteType,
 								  char foreignMatchType,
+								  Node *conExpr,
 								  const char *conBin,
 								  const char *conSrc);
 

src/include/catalog/pg_constraint.h

@@ -544,13 +544,19 @@ from (select oid from pg_class where relname = 'atest1') as t1;
 \c regression
 DROP FUNCTION testfunc2(int);
 DROP FUNCTION testfunc4(boolean);
-DROP TABLE atest1;
-DROP TABLE atest2;
-DROP TABLE atest3;
 DROP VIEW atestv1;
 DROP VIEW atestv2;
-DROP VIEW atestv3;
+-- this should cascade to drop atestv4
+DROP VIEW atestv3 CASCADE;
+NOTICE:  Drop cascades to rule _RETURN on view atestv3
+NOTICE:  Drop cascades to rule _RETURN on view atestv4
+NOTICE:  Drop cascades to view atestv4
+-- this should complain "does not exist"
 DROP VIEW atestv4;
+ERROR:  view "atestv4" does not exist
+DROP TABLE atest1;
+DROP TABLE atest2;
+DROP TABLE atest3;
 DROP GROUP regressgroup1;
 DROP GROUP regressgroup2;
 DROP USER regressuser1;