Lock all relations referred to in updatable views

Even views considered "simple" enough to be automatically updatable may
have mulitple relations involved (eg: in a where clause).  We need to
make sure and lock those relations when rewriting the query.

Back-patch to 9.3 where updatable views were added.

Pointed out by Andres, patch thanks to Dean Rasheed.

diff --git a/src/backend/rewrite/rewriteHandler.c b/src/backend/rewrite/rewriteHandler.c
index cb65c0502effc01212e240cbd8e1f14462aef75f..1c70557d3153005f7340a1d5c741779276dedbbd 100644 (file)
--- a/src/backend/rewrite/rewriteHandler.c
+++ b/src/backend/rewrite/rewriteHandler.c
@@ -2626,6 +2626,21 @@ rewriteTargetView(Query *parsetree, Relation view)
 
        heap_close(base_rel, NoLock);
 
+       /*
+        * If the view query contains any sublink subqueries then we need to also
+        * acquire locks on any relations they refer to.  We know that there won't
+        * be any subqueries in the range table or CTEs, so we can skip those, as
+        * in AcquireRewriteLocks.
+        */
+       if (viewquery->hasSubLinks)
+       {
+               acquireLocksOnSubLinks_context context;
+
+               context.for_execute = true;
+               query_tree_walker(viewquery, acquireLocksOnSubLinks, &context,
+                                                 QTW_IGNORE_RC_SUBQUERIES);
+       }
+
        /*
         * Create a new target RTE describing the base relation, and add it to the
         * outer query's rangetable.  (What's happening in the next few steps is