From aeaaf520f409cf314f97c811d2713c99858f035d Mon Sep 17 00:00:00 2001 From: Tom Lane Date: Mon, 21 Nov 2022 15:37:10 -0500 Subject: [PATCH] Mark pageinspect's disk-accessing functions as parallel restricted. These functions have been marked parallel safe, but the buildfarm's response to commit e2933a6e1 exposed the flaw in that thinking: if you try to use them on a temporary table, and they run inside a parallel worker, they'll fail with "cannot access temporary tables during a parallel operation". Fix that by marking them parallel restricted instead. Maybe someday we'll have a better answer and can reverse this decision. Back-patch to v15. To go back further, we'd have to devise variant versions of pre-1.10 pageinspect versions. Given the lack of field complaints, it doesn't seem worth the trouble. We'll just deem this case unsupported pre-v15. (If anyone does complain, it might be good enough to update the markings manually in their DBs.) Discussion: https://postgr.es/m/E1ox94a-000EHu-VH@gemulon.postgresql.org --- contrib/pageinspect/Makefile | 3 +- contrib/pageinspect/meson.build | 1 + .../pageinspect/pageinspect--1.10--1.11.sql | 28 +++++++++++++++++++ contrib/pageinspect/pageinspect.control | 2 +- 4 files changed, 32 insertions(+), 2 deletions(-) create mode 100644 contrib/pageinspect/pageinspect--1.10--1.11.sql diff --git a/contrib/pageinspect/Makefile b/contrib/pageinspect/Makefile index 5c0736564a..ad5a3ac511 100644 --- a/contrib/pageinspect/Makefile +++ b/contrib/pageinspect/Makefile @@ -13,7 +13,8 @@ OBJS = \ rawpage.o EXTENSION = pageinspect -DATA = pageinspect--1.9--1.10.sql pageinspect--1.8--1.9.sql \ +DATA = pageinspect--1.10--1.11.sql \ + pageinspect--1.9--1.10.sql pageinspect--1.8--1.9.sql \ pageinspect--1.7--1.8.sql pageinspect--1.6--1.7.sql \ pageinspect--1.5.sql pageinspect--1.5--1.6.sql \ pageinspect--1.4--1.5.sql pageinspect--1.3--1.4.sql \ diff --git a/contrib/pageinspect/meson.build b/contrib/pageinspect/meson.build index 3ec50b9445..25fa7dc20c 100644 --- a/contrib/pageinspect/meson.build +++ b/contrib/pageinspect/meson.build @@ -33,6 +33,7 @@ install_data( 'pageinspect--1.7--1.8.sql', 'pageinspect--1.8--1.9.sql', 'pageinspect--1.9--1.10.sql', + 'pageinspect--1.10--1.11.sql', 'pageinspect.control', kwargs: contrib_data_args, ) diff --git a/contrib/pageinspect/pageinspect--1.10--1.11.sql b/contrib/pageinspect/pageinspect--1.10--1.11.sql new file mode 100644 index 0000000000..8fa5e105bc --- /dev/null +++ b/contrib/pageinspect/pageinspect--1.10--1.11.sql @@ -0,0 +1,28 @@ +/* contrib/pageinspect/pageinspect--1.10--1.11.sql */ + +-- complain if script is sourced in psql, rather than via ALTER EXTENSION +\echo Use "ALTER EXTENSION pageinspect UPDATE TO '1.11'" to load this file. \quit + +-- +-- Functions that fetch relation pages must be PARALLEL RESTRICTED, +-- not PARALLEL SAFE, otherwise they will fail when run on a +-- temporary table in a parallel worker process. +-- + +ALTER FUNCTION get_raw_page(text, int8) PARALLEL RESTRICTED; +ALTER FUNCTION get_raw_page(text, text, int8) PARALLEL RESTRICTED; +-- tuple_data_split must be restricted because it may fetch TOAST data. +ALTER FUNCTION tuple_data_split(oid, bytea, integer, integer, text) PARALLEL RESTRICTED; +ALTER FUNCTION tuple_data_split(oid, bytea, integer, integer, text, bool) PARALLEL RESTRICTED; +-- heap_page_item_attrs must be restricted because it calls tuple_data_split. +ALTER FUNCTION heap_page_item_attrs(bytea, regclass, bool) PARALLEL RESTRICTED; +ALTER FUNCTION heap_page_item_attrs(bytea, regclass) PARALLEL RESTRICTED; +ALTER FUNCTION bt_metap(text) PARALLEL RESTRICTED; +ALTER FUNCTION bt_page_stats(text, int8) PARALLEL RESTRICTED; +ALTER FUNCTION bt_page_items(text, int8) PARALLEL RESTRICTED; +ALTER FUNCTION hash_bitmap_info(regclass, int8) PARALLEL RESTRICTED; +-- brin_page_items might be parallel safe, because it seems to touch +-- only index metadata, but I don't think there's a point in risking it. +-- Likewise for gist_page_items. +ALTER FUNCTION brin_page_items(bytea, regclass) PARALLEL RESTRICTED; +ALTER FUNCTION gist_page_items(bytea, regclass) PARALLEL RESTRICTED; diff --git a/contrib/pageinspect/pageinspect.control b/contrib/pageinspect/pageinspect.control index 7cdf37913d..f277413dd8 100644 --- a/contrib/pageinspect/pageinspect.control +++ b/contrib/pageinspect/pageinspect.control @@ -1,5 +1,5 @@ # pageinspect extension comment = 'inspect the contents of database pages at a low level' -default_version = '1.10' +default_version = '1.11' module_pathname = '$libdir/pageinspect' relocatable = true