fanfuxiaoran commented on code in PR #705:
URL: https://github.com/apache/cloudberry/pull/705#discussion_r1867108142
##########
src/backend/optimizer/plan/aqumv.c:
##########
@@ -293,69 +325,195 @@ answer_query_using_materialized_views(PlannerInfo *root,
context = aqumv_init_context(viewQuery->targetList,
matviewRel->rd_att);
- /*
- * Process and rewrite target list, return false if failed.
- */
- if(!aqumv_process_targetlist(context, parse->targetList,
&mv_final_tlist))
+ if (!parse->hasAggs && viewQuery->hasAggs)
continue;
- viewQuery->targetList = mv_final_tlist;
+ if (parse->hasAggs && viewQuery->hasAggs)
+ {
+ if (parse->hasDistinctOn ||
+ parse->distinctClause != NIL ||
+ parse->groupClause != NIL ||
+ parse->groupingSets != NIL ||
+ parse->groupDistinct)
+ continue;
+
+ /* No Group by now. */
+ if (viewQuery->hasDistinctOn ||
+ viewQuery->distinctClause != NIL ||
+ viewQuery->groupClause != NIL ||
+ viewQuery->groupingSets != NIL ||
+ viewQuery->groupDistinct ||
+ viewQuery->havingQual != NULL || /* HAVING
clause is not supported on IMMV yet. */
+ limit_needed(viewQuery)) /* LIMIT, OFFSET is
not supported on IMMV yet. */
+ continue;
- /*
- * NB: Update processed_tlist again in case that tlist has been
changed.
- */
- preprocess_targetlist(subroot);
+ /*
+ * There is a trick for ORDER BY for both origin query
and view query.
+ * As we has no Groupy By here, the aggregation results
would be either one or
+ * zero rows that make the Order By clause pointless.
+ * We could avoid considering the sort columns if it's
a junk for view matching.
+ * This in-place update raw_processed_tlist.
+ */
+ if (parse->sortClause != NIL || viewQuery->sortClause
!= NIL)
+ {
+ ListCell *lc;
+ ListCell *lcc;
+
+ foreach (lc, raw_processed_tlist)
+ {
+ TargetEntry *tle = (TargetEntry *)
lfirst(lc);
+ if (!tle->resjunk || (0 ==
tle->ressortgroupref))
+ continue;
+
+ foreach (lcc, parse->sortClause)
+ {
+ SortGroupClause *srt =
(SortGroupClause *) lfirst(lcc);
+ if (tle->ressortgroupref ==
srt->tleSortGroupRef)
+
foreach_delete_current(raw_processed_tlist, lc);
+ }
+ }
+ /* Earse view's sort caluse, it's ok to let
alone view's target list. */
+ viewQuery->sortClause = NIL;
+ }
- /*
- * We have successfully processed target list, and all columns
in Aggrefs
- * could be computed from viewQuery.
- */
- viewQuery->hasAggs = parse->hasAggs;
- viewQuery->hasDistinctOn = parse->hasDistinctOn;
- /*
- * For HAVING quals have aggregations, we have already
processed them in
- * Aggrefs during aqumv_process_targetlist().
- * For HAVING quals don't have aggregations, they may be pushed
down to
- * jointree's quals and would be processed in post_quals later.
- * Set havingQual before we preprocess_aggrefs for that.
- */
- viewQuery->havingQual = parse->havingQual;
- if (viewQuery->hasAggs)
- {
- preprocess_aggrefs(subroot, (Node *)
subroot->processed_tlist);
- preprocess_aggrefs(subroot, viewQuery->havingQual);
+ /*
+ * Process Limit:
+ * The result would be one row at most.
+ * View may be useful even Limit clause is different,
ex:
+ * View:
+ * create incremental materialized view mv as
+ * select count(*) as mc1 from t;
+ * Query:
+ * select count(*) from t limit 1;
+ * Rewrite to:
+ * select mc1 from mv limit 1;
+ */
+ /* Below logic is based on view has no LIMIT/OFFSET. */
+ Assert(!limit_needed(viewQuery));
+ if (limit_needed(parse))
+ {
+ Node *node;
+ /*
+ * AQUMV don't support sublinks now.
+ * Use query's LIMIT/OFFSET if they are const
in case.
+ */
+ node = parse->limitCount;
+ if (node && !IsA(node, Const))
+ continue;
+
+ node = parse->limitOffset;
+ if (node && !IsA(node, Const))
+ continue;
+
+ viewQuery->limitCount =
copyObject(parse->limitCount);
+ viewQuery->limitOffset =
copyObject(parse->limitOffset);
+ viewQuery->limitOption = parse->limitOption;
+ }
+
+ preprocess_qual_conditions(subroot, (Node *)
viewQuery->jointree);
+
+ if(!aqumv_process_from_quals(parse->jointree->quals,
viewQuery->jointree->quals, &post_quals))
+ continue;
+
+ if (post_quals != NIL)
Review Comment:
Got it . Exactly, the `post_quals` cannot apply on the agg result.
Thanks for your explanation ,
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