From 6331de1d44f01d408aa48c5c996bae8932f7a072 Mon Sep 17 00:00:00 2001 From: Tom Lane Date: Tue, 5 Nov 2013 11:31:35 -0500 Subject: [PATCH] Fix some obsolete information in src/backend/optimizer/README. Constant quals aren't handled the same way they used to be. Also, add mention of a couple more major steps in grouping_planner. Per complaint a couple months back from Etsuro Fujita. --- src/backend/optimizer/README | 7 ++----- 1 file changed, 2 insertions(+), 5 deletions(-) diff --git a/src/backend/optimizer/README b/src/backend/optimizer/README index 99203968ba..88cdbc3294 100644 --- a/src/backend/optimizer/README +++ b/src/backend/optimizer/README @@ -297,9 +297,6 @@ planner() handle UNION/INTERSECT/EXCEPT, GROUP BY, HAVING, aggregates, ORDER BY, DISTINCT, LIMIT --query_planner() - pull out constant quals, which can be used to gate execution of the - whole plan (if any are found, we make a top-level Result node - to do the gating) make list of base relations used in query split up the qual into restrictions (a=1) and joins (b=c) find qual clauses that enable merge and hash joins @@ -318,11 +315,11 @@ planner() Back at standard_join_search(), apply set_cheapest() to extract the cheapest path for each newly constructed joinrel. Loop back if this wasn't the top join level. - Back at query_planner: - put back any constant quals by adding a Result node Back at grouping_planner: + convert Path tree returned by query_planner into a Plan tree do grouping(GROUP) do aggregates + do window functions make unique(DISTINCT) make sort(ORDER BY) make limit(LIMIT/OFFSET) -- 2.40.0