Change the rules for inherited CHECK constraints to be essentially the same

as those for inherited columns; that is, it's no longer allowed for a child
table to not have a check constraint matching one that exists on a parent.
This satisfies the principle of least surprise (rows selected from the parent
will always appear to meet its check constraints) and eliminates some
longstanding bogosity in pg_dump, which formerly had to guess about whether
check constraints were really inherited or not.

The implementation involves adding conislocal and coninhcount columns to
pg_constraint (paralleling attislocal and attinhcount in pg_attribute)
and refactoring various ALTER TABLE actions to be more like those for
columns.

Alex Hunsaker, Nikhil Sontakke, Tom Lane

1 files changed, 4 insertions, 43 deletions

diff --git a/src/bin/pg_dump/common.c b/src/bin/pg_dump/common.c
index 2d41a52e191..8950dee0ca8 100644
--- a/src/bin/pg_dump/common.c
+++ b/src/bin/pg_dump/common.c
@@ -11,7 +11,7 @@
  *
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/bin/pg_dump/common.c,v 1.103 2008/03/27 03:57:33 tgl Exp $
+ *	  $PostgreSQL: pgsql/src/bin/pg_dump/common.c,v 1.104 2008/05/09 23:32:04 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -62,8 +62,7 @@ static DumpableObject **oprinfoindex;
 
 static void flagInhTables(TableInfo *tbinfo, int numTables,
 			  InhInfo *inhinfo, int numInherits);
-static void flagInhAttrs(TableInfo *tbinfo, int numTables,
-			 InhInfo *inhinfo, int numInherits);
+static void flagInhAttrs(TableInfo *tblinfo, int numTables);
 static DumpableObject **buildIndexArray(void *objArray, int numObjs,
 				Size objSize);
 static int	DOCatalogIdCompare(const void *p1, const void *p2);
@@ -191,7 +190,7 @@ getSchemaData(int *numTablesPtr)
 
 	if (g_verbose)
 		write_msg(NULL, "flagging inherited columns in subtables\n");
-	flagInhAttrs(tblinfo, numTables, inhinfo, numInherits);
+	flagInhAttrs(tblinfo, numTables);
 
 	if (g_verbose)
 		write_msg(NULL, "reading indexes\n");
@@ -257,8 +256,7 @@ flagInhTables(TableInfo *tblinfo, int numTables,
  * modifies tblinfo
  */
 static void
-flagInhAttrs(TableInfo *tblinfo, int numTables,
-			 InhInfo *inhinfo, int numInherits)
+flagInhAttrs(TableInfo *tblinfo, int numTables)
 {
 	int			i,
 				j,
@@ -414,43 +412,6 @@ flagInhAttrs(TableInfo *tblinfo, int numTables,
 					tbinfo->inhAttrs[j] = false;
 			}
 		}
-
-		/*
-		 * Check for inherited CHECK constraints.  We assume a constraint is
-		 * inherited if its name matches the name of any constraint in the
-		 * parent.	Originally this code tried to compare the expression
-		 * texts, but that can fail if the parent and child tables are in
-		 * different schemas, because reverse-listing of function calls may
-		 * produce different text (schema-qualified or not) depending on
-		 * search path.  We really need a more bulletproof way of detecting
-		 * inherited constraints --- pg_constraint should record this
-		 * explicitly!
-		 */
-		for (j = 0; j < tbinfo->ncheck; j++)
-		{
-			ConstraintInfo *constr;
-
-			constr = &(tbinfo->checkexprs[j]);
-
-			for (k = 0; k < numParents; k++)
-			{
-				int			l;
-
-				parent = parents[k];
-				for (l = 0; l < parent->ncheck; l++)
-				{
-					ConstraintInfo *pconstr = &(parent->checkexprs[l]);
-
-					if (strcmp(pconstr->dobj.name, constr->dobj.name) == 0)
-					{
-						constr->coninherited = true;
-						break;
-					}
-				}
-				if (constr->coninherited)
-					break;
-			}
-		}
 	}
 }