From: Fujii Masao <fujii@postgresql.org>
Date: Mon, 6 Apr 2026 04:19:45 +0000 (+0900)
Subject: Simplify redundant current_database() subqueries in stats.sql regression test
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=d78a4f0bf058906c5cfd25c815ccbdf18013b312;p=thirdparty%2Fpostgresql.git

Simplify redundant current_database() subqueries in stats.sql regression test

Previously the stats.sql regression test used conditions like
"datname = (SELECT current_database())" to check the current database name.

The subquery is unnecessary, so this commit simplifies these expressions to
"datname = current_database()".

Author: Chao Li <lic@highgo.com>
Reviewed-by: Fujii Masao <masao.fujii@gmail.com>
Discussion: https://postgr.es/m/A1535A8F-65AF-4C3D-ACBE-25891CB5D38B@gmail.com
---

diff --git a/src/test/regress/expected/stats.out b/src/test/regress/expected/stats.out
index 35632f83052..55009cfcc7d 100644
--- a/src/test/regress/expected/stats.out
+++ b/src/test/regress/expected/stats.out
@@ -947,7 +947,7 @@ SELECT (n_tup_ins + n_tup_upd) > 0 AS has_data FROM pg_stat_all_tables
 -- Test that various stats views are being properly populated
 -----
 -- Test that sessions is incremented when a new session is started in pg_stat_database
-SELECT sessions AS db_stat_sessions FROM pg_stat_database WHERE datname = (SELECT current_database()) \gset
+SELECT sessions AS db_stat_sessions FROM pg_stat_database WHERE datname = current_database() \gset
 \c
 SELECT pg_stat_force_next_flush();
  pg_stat_force_next_flush 
@@ -955,7 +955,7 @@ SELECT pg_stat_force_next_flush();
  
 (1 row)
 
-SELECT sessions > :db_stat_sessions FROM pg_stat_database WHERE datname = (SELECT current_database());
+SELECT sessions > :db_stat_sessions FROM pg_stat_database WHERE datname = current_database();
  ?column? 
 ----------
  t
@@ -1157,8 +1157,8 @@ SELECT pg_stat_reset();
  
 (1 row)
 
-SELECT stats_reset AS db_reset_ts FROM pg_stat_database WHERE datname = (SELECT current_database()) \gset
-SELECT stats_reset AS dbc_reset_ts FROM pg_stat_database_conflicts WHERE datname = (SELECT current_database()) \gset
+SELECT stats_reset AS db_reset_ts FROM pg_stat_database WHERE datname = current_database() \gset
+SELECT stats_reset AS dbc_reset_ts FROM pg_stat_database_conflicts WHERE datname = current_database() \gset
 SELECT :'db_reset_ts'::timestamptz = :'dbc_reset_ts'::timestamptz;
  ?column? 
 ----------
@@ -1171,13 +1171,13 @@ SELECT pg_stat_reset();
  
 (1 row)
 
-SELECT stats_reset > :'db_reset_ts'::timestamptz FROM pg_stat_database WHERE datname = (SELECT current_database());
+SELECT stats_reset > :'db_reset_ts'::timestamptz FROM pg_stat_database WHERE datname = current_database();
  ?column? 
 ----------
  t
 (1 row)
 
-SELECT stats_reset > :'dbc_reset_ts'::timestamptz FROM pg_stat_database_conflicts WHERE datname = (SELECT current_database());
+SELECT stats_reset > :'dbc_reset_ts'::timestamptz FROM pg_stat_database_conflicts WHERE datname = current_database();
  ?column? 
 ----------
  t
diff --git a/src/test/regress/sql/stats.sql b/src/test/regress/sql/stats.sql
index 65d8968c83e..158f3ca6ebe 100644
--- a/src/test/regress/sql/stats.sql
+++ b/src/test/regress/sql/stats.sql
@@ -432,10 +432,10 @@ SELECT (n_tup_ins + n_tup_upd) > 0 AS has_data FROM pg_stat_all_tables
 -----
 
 -- Test that sessions is incremented when a new session is started in pg_stat_database
-SELECT sessions AS db_stat_sessions FROM pg_stat_database WHERE datname = (SELECT current_database()) \gset
+SELECT sessions AS db_stat_sessions FROM pg_stat_database WHERE datname = current_database() \gset
 \c
 SELECT pg_stat_force_next_flush();
-SELECT sessions > :db_stat_sessions FROM pg_stat_database WHERE datname = (SELECT current_database());
+SELECT sessions > :db_stat_sessions FROM pg_stat_database WHERE datname = current_database();
 
 -- Test pg_stat_checkpointer checkpointer-related stats, together with pg_stat_wal
 SELECT num_requested AS rqst_ckpts_before FROM pg_stat_checkpointer \gset
@@ -529,12 +529,12 @@ SELECT pg_stat_reset_shared('unknown');
 -- have a baseline for comparison. The same for pg_stat_database_conflicts as it shares
 -- the same stats_reset as pg_stat_database.
 SELECT pg_stat_reset();
-SELECT stats_reset AS db_reset_ts FROM pg_stat_database WHERE datname = (SELECT current_database()) \gset
-SELECT stats_reset AS dbc_reset_ts FROM pg_stat_database_conflicts WHERE datname = (SELECT current_database()) \gset
+SELECT stats_reset AS db_reset_ts FROM pg_stat_database WHERE datname = current_database() \gset
+SELECT stats_reset AS dbc_reset_ts FROM pg_stat_database_conflicts WHERE datname = current_database() \gset
 SELECT :'db_reset_ts'::timestamptz = :'dbc_reset_ts'::timestamptz;
 SELECT pg_stat_reset();
-SELECT stats_reset > :'db_reset_ts'::timestamptz FROM pg_stat_database WHERE datname = (SELECT current_database());
-SELECT stats_reset > :'dbc_reset_ts'::timestamptz FROM pg_stat_database_conflicts WHERE datname = (SELECT current_database());
+SELECT stats_reset > :'db_reset_ts'::timestamptz FROM pg_stat_database WHERE datname = current_database();
+SELECT stats_reset > :'dbc_reset_ts'::timestamptz FROM pg_stat_database_conflicts WHERE datname = current_database();
 
 -- Test that reset works for pg_statio_all_sequences