From d3c0cc4447307a2ffbcff8274573b544294e583c Mon Sep 17 00:00:00 2001 From: Michael Paquier Date: Mon, 26 Dec 2022 08:00:55 +0900 Subject: [PATCH] Switch query fixing aclitems in ~15 from O(N^2) to O(N) in upgrade_adapt.sql f4f2f2b was doing a sequential scan of pg_class before checking if a relation had attributes dependent on aclitem as data typewhen building the set of ALTER TABLE queries, but it would be costly on a regression database. While on it, make the query style more consistent with the rest. Reported-by: Justin Pryzby Discussion: https://postgr.es/m/20221223032724.GQ1153@telsasoft.com --- src/bin/pg_upgrade/upgrade_adapt.sql | 26 +++++++++++--------------- 1 file changed, 11 insertions(+), 15 deletions(-) diff --git a/src/bin/pg_upgrade/upgrade_adapt.sql b/src/bin/pg_upgrade/upgrade_adapt.sql index 54920f54f5..a368a51ff5 100644 --- a/src/bin/pg_upgrade/upgrade_adapt.sql +++ b/src/bin/pg_upgrade/upgrade_adapt.sql @@ -95,25 +95,21 @@ DROP OPERATOR public.#@%# (pg_catalog.int8, NONE); -- The internal format of "aclitem" has changed in 16, so replace it with -- text type in tables. \if :oldpgversion_le15 -DO $$ +DO $stmt$ DECLARE - rec text; - col text; + rec record; BEGIN FOR rec in - SELECT oid::regclass::text - FROM pg_class - WHERE relname !~ '^pg_' - AND relkind IN ('r') + SELECT oid::regclass::text as rel, attname as col + FROM pg_class c, pg_attribute a + WHERE c.relname !~ '^pg_' + AND c.relkind IN ('r') + AND a.attrelid = c.oid + AND a.atttypid = 'aclitem'::regtype ORDER BY 1 LOOP - FOR col in SELECT attname FROM pg_attribute - WHERE attrelid::regclass::text = rec - AND atttypid = 'aclitem'::regtype - LOOP - EXECUTE 'ALTER TABLE ' || quote_ident(rec) || ' ALTER COLUMN ' || - quote_ident(col) || ' SET DATA TYPE text'; - END LOOP; + EXECUTE 'ALTER TABLE ' || quote_ident(rec.rel) || ' ALTER COLUMN ' || + quote_ident(rec.col) || ' SET DATA TYPE text'; END LOOP; - END; $$; + END; $stmt$; \endif