diff options
Diffstat (limited to 'src/backend/rewrite/rewriteHandler.c')
| -rw-r--r-- | src/backend/rewrite/rewriteHandler.c | 34 |
1 files changed, 22 insertions, 12 deletions
diff --git a/src/backend/rewrite/rewriteHandler.c b/src/backend/rewrite/rewriteHandler.c index 1b8e7b08a51..bc29e1790ef 100644 --- a/src/backend/rewrite/rewriteHandler.c +++ b/src/backend/rewrite/rewriteHandler.c @@ -2033,6 +2033,9 @@ fireRules(Query *parsetree, * * Caller should have verified that the relation is a view, and therefore * we should find an ON SELECT action. + * + * Note that the pointer returned is into the relcache and therefore must + * be treated as read-only to the caller and not modified or scribbled on. */ Query * get_view_query(Relation view) @@ -2620,9 +2623,16 @@ rewriteTargetView(Query *parsetree, Relation view) List *view_targetlist; ListCell *lc; - /* The view must be updatable, else fail */ - viewquery = get_view_query(view); + /* + * Get the Query from the view's ON SELECT rule. We're going to munge the + * Query to change the view's base relation into the target relation, + * along with various other changes along the way, so we need to make a + * copy of it (get_view_query() returns a pointer into the relcache, so we + * have to treat it as read-only). + */ + viewquery = copyObject(get_view_query(view)); + /* The view must be updatable, else fail */ auto_update_detail = view_query_is_auto_updatable(viewquery, parsetree->commandType != CMD_DELETE); @@ -2786,7 +2796,7 @@ rewriteTargetView(Query *parsetree, Relation view) * outer query. Perhaps someday we should refactor things enough so that * we can share code with the planner.) */ - new_rte = (RangeTblEntry *) copyObject(base_rte); + new_rte = (RangeTblEntry *) base_rte; parsetree->rtable = lappend(parsetree->rtable, new_rte); new_rt_index = list_length(parsetree->rtable); @@ -2798,14 +2808,14 @@ rewriteTargetView(Query *parsetree, Relation view) new_rte->inh = false; /* - * Make a copy of the view's targetlist, adjusting its Vars to reference - * the new target RTE, ie make their varnos be new_rt_index instead of - * base_rt_index. There can be no Vars for other rels in the tlist, so - * this is sufficient to pull up the tlist expressions for use in the - * outer query. The tlist will provide the replacement expressions used - * by ReplaceVarsFromTargetList below. + * Adjust the view's targetlist Vars to reference the new target RTE, ie + * make their varnos be new_rt_index instead of base_rt_index. There can + * be no Vars for other rels in the tlist, so this is sufficient to pull + * up the tlist expressions for use in the outer query. The tlist will + * provide the replacement expressions used by ReplaceVarsFromTargetList + * below. */ - view_targetlist = copyObject(viewquery->targetList); + view_targetlist = viewquery->targetList; ChangeVarNodes((Node *) view_targetlist, base_rt_index, @@ -2956,7 +2966,7 @@ rewriteTargetView(Query *parsetree, Relation view) if (parsetree->commandType != CMD_INSERT && viewquery->jointree->quals != NULL) { - Node *viewqual = (Node *) copyObject(viewquery->jointree->quals); + Node *viewqual = (Node *) viewquery->jointree->quals; ChangeVarNodes(viewqual, base_rt_index, new_rt_index, 0); @@ -3035,7 +3045,7 @@ rewriteTargetView(Query *parsetree, Relation view) if (viewquery->jointree->quals != NULL) { - wco->qual = (Node *) copyObject(viewquery->jointree->quals); + wco->qual = (Node *) viewquery->jointree->quals; ChangeVarNodes(wco->qual, base_rt_index, new_rt_index, 0); /* |