WITH CHECK OPTION support for auto-updatable VIEWs

For simple views which are automatically updatable, this patch allows
the user to specify what level of checking should be done on records
being inserted or updated.  For 'LOCAL CHECK', new tuples are validated
against the conditionals of the view they are being inserted into, while
for 'CASCADED CHECK' the new tuples are validated against the
conditionals for all views involved (from the top down).

This option is part of the SQL specification.

Dean Rasheed, reviewed by Pavel Stehule

1 files changed, 33 insertions, 0 deletions

diff --git a/src/backend/executor/nodeModifyTable.c b/src/backend/executor/nodeModifyTable.c
index 8fe5f1d427..15f5dccb82 100644
--- a/src/backend/executor/nodeModifyTable.c
+++ b/src/backend/executor/nodeModifyTable.c
@@ -281,6 +281,10 @@ ExecInsert(TupleTableSlot *slot,
 
 	list_free(recheckIndexes);
 
+	/* Check any WITH CHECK OPTION constraints */
+	if (resultRelInfo->ri_WithCheckOptions != NIL)
+		ExecWithCheckOptions(resultRelInfo, slot, estate);
+
 	/* Process RETURNING if present */
 	if (resultRelInfo->ri_projectReturning)
 		return ExecProcessReturning(resultRelInfo->ri_projectReturning,
@@ -777,6 +781,10 @@ lreplace:;
 
 	list_free(recheckIndexes);
 
+	/* Check any WITH CHECK OPTION constraints */
+	if (resultRelInfo->ri_WithCheckOptions != NIL)
+		ExecWithCheckOptions(resultRelInfo, slot, estate);
+
 	/* Process RETURNING if present */
 	if (resultRelInfo->ri_projectReturning)
 		return ExecProcessReturning(resultRelInfo->ri_projectReturning,
@@ -1130,6 +1138,31 @@ ExecInitModifyTable(ModifyTable *node, EState *estate, int eflags)
 	estate->es_result_relation_info = saved_resultRelInfo;
 
 	/*
+	 * Initialize any WITH CHECK OPTION constraints if needed.
+	 */
+	resultRelInfo = mtstate->resultRelInfo;
+	i = 0;
+	foreach(l, node->withCheckOptionLists)
+	{
+		List	   *wcoList = (List *) lfirst(l);
+		List	   *wcoExprs = NIL;
+		ListCell   *ll;
+
+		foreach(ll, wcoList)
+		{
+			WithCheckOption *wco = (WithCheckOption *) lfirst(ll);
+			ExprState  *wcoExpr = ExecInitExpr((Expr *) wco->qual,
+											   mtstate->mt_plans[i]);
+			wcoExprs = lappend(wcoExprs, wcoExpr);
+		}
+
+		resultRelInfo->ri_WithCheckOptions = wcoList;
+		resultRelInfo->ri_WithCheckOptionExprs = wcoExprs;
+		resultRelInfo++;
+		i++;
+	}
+
+	/*
 	 * Initialize RETURNING projections if needed.
 	 */
 	if (node->returningLists)