From 5bde1651bbba9984dc32bbeb68b329cfd3f92767 Mon Sep 17 00:00:00 2001 From: Michael Paquier Date: Wed, 27 Mar 2019 11:35:12 +0900 Subject: [PATCH] Switch function current_schema[s]() to be parallel-unsafe When invoked for the first time in a session, current_schema() and current_schemas() can finish by creating a temporary schema. Currently those functions are parallel-safe, however if for a reason or another they get launched across multiple parallel workers, they would fail when attempting to create a temporary schema as temporary contexts are not supported in this case. The original issue has been spotted by buildfarm members crake and lapwing, after commit c5660e0 has introduced the first regression tests based on current_schema() in the tree. After that, 396676b has introduced a workaround to avoid parallel plans but that was not completely right either. Catversion is bumped. Author: Michael Paquier Reviewed-by: Daniel Gustafsson Discussion: https://postgr.es/m/20190118024618.GF1883@paquier.xyz --- src/include/catalog/catversion.h | 2 +- src/include/catalog/pg_proc.dat | 8 ++++---- src/test/regress/expected/temp.out | 5 +---- src/test/regress/sql/temp.sql | 5 +---- 4 files changed, 7 insertions(+), 13 deletions(-) diff --git a/src/include/catalog/catversion.h b/src/include/catalog/catversion.h index c1e1d601ec5..f01087614e4 100644 --- a/src/include/catalog/catversion.h +++ b/src/include/catalog/catversion.h @@ -53,6 +53,6 @@ */ /* yyyymmddN */ -#define CATALOG_VERSION_NO 201903251 +#define CATALOG_VERSION_NO 201903271 #endif diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat index acf1131b521..8cf77297e14 100644 --- a/src/include/catalog/pg_proc.dat +++ b/src/include/catalog/pg_proc.dat @@ -2787,11 +2787,11 @@ prosrc => 'name_text' }, { oid => '1402', descr => 'current schema name', - proname => 'current_schema', provolatile => 's', prorettype => 'name', - proargtypes => '', prosrc => 'current_schema' }, + proname => 'current_schema', provolatile => 's', proparallel => 'u', + prorettype => 'name', proargtypes => '', prosrc => 'current_schema' }, { oid => '1403', descr => 'current schema search list', - proname => 'current_schemas', provolatile => 's', prorettype => '_name', - proargtypes => 'bool', prosrc => 'current_schemas' }, + proname => 'current_schemas', provolatile => 's', proparallel => 'u', + prorettype => '_name', proargtypes => 'bool', prosrc => 'current_schemas' }, { oid => '1404', descr => 'substitute portion of string', proname => 'overlay', prorettype => 'text', diff --git a/src/test/regress/expected/temp.out b/src/test/regress/expected/temp.out index 056e5ecf33c..ad7d5581911 100644 --- a/src/test/regress/expected/temp.out +++ b/src/test/regress/expected/temp.out @@ -360,11 +360,8 @@ prepare transaction 'twophase_tab'; ERROR: cannot PREPARE a transaction that has operated on temporary objects -- Corner case: current_schema may create a temporary schema if namespace -- creation is pending, so check after that. First reset the connection --- to remove the temporary namespace, and make sure that non-parallel plans --- are used. +-- to remove the temporary namespace. \c - -SET max_parallel_workers = 0; -SET max_parallel_workers_per_gather = 0; SET search_path TO 'pg_temp'; BEGIN; SELECT current_schema() ~ 'pg_temp' AS is_temp_schema; diff --git a/src/test/regress/sql/temp.sql b/src/test/regress/sql/temp.sql index 17366a33a91..e634ddb9ca4 100644 --- a/src/test/regress/sql/temp.sql +++ b/src/test/regress/sql/temp.sql @@ -274,11 +274,8 @@ prepare transaction 'twophase_tab'; -- Corner case: current_schema may create a temporary schema if namespace -- creation is pending, so check after that. First reset the connection --- to remove the temporary namespace, and make sure that non-parallel plans --- are used. +-- to remove the temporary namespace. \c - -SET max_parallel_workers = 0; -SET max_parallel_workers_per_gather = 0; SET search_path TO 'pg_temp'; BEGIN; SELECT current_schema() ~ 'pg_temp' AS is_temp_schema;