v1-0001-Add-no-argument-support-for-pg_stat_reset_slru.text

From 8b70989fcf88e92cd005852dd75a770324f3de3e Mon Sep 17 00:00:00 2001
From: Bharath Rupireddy <bharath.rupireddyforpostgres@gmail.com>
Date: Wed, 8 Nov 2023 08:33:19 +0000
Subject: [PATCH v1] Add no argument support for pg_stat_reset_slru

Presently, one needs to specify pg_stat_reset_slru input argument
as NULL to reset all SLRU stats which looks a bit odd confusing to
the user. This commit changes the API by adding a DEFAULT NULL to
input parameter in system_functions.sql allowing users to not pass
anything as input to reset all SLRU stats.
---
 doc/src/sgml/monitoring.sgml             | 6 +++---
 src/backend/catalog/system_functions.sql | 7 +++++++
 src/include/catalog/pg_proc.dat          | 3 ++-
 src/test/regress/expected/stats.out      | 2 +-
 src/test/regress/sql/stats.sql           | 2 +-
 5 files changed, 14 insertions(+), 6 deletions(-)

diff --git a/doc/src/sgml/monitoring.sgml b/doc/src/sgml/monitoring.sgml
index a0257fea0c..87873a3c29 100644
--- a/doc/src/sgml/monitoring.sgml
+++ b/doc/src/sgml/monitoring.sgml
@@ -4844,9 +4844,9 @@ description | Waiting for a newly initialized WAL file to reach durable storage
        </para>
        <para>
         Resets statistics to zero for a single SLRU cache, or for all SLRUs in
-        the cluster.  If the argument is NULL, all counters shown in
-        the <structname>pg_stat_slru</structname> view for all SLRU caches are
-        reset.  The argument can be one of
+        the cluster.  If the argument is NULL or not specified, all counters
+        shown in the <structname>pg_stat_slru</structname> view for all SLRU
+        caches are reset. The argument can be one of
         <literal>CommitTs</literal>,
         <literal>MultiXactMember</literal>,
         <literal>MultiXactOffset</literal>,
diff --git a/src/backend/catalog/system_functions.sql b/src/backend/catalog/system_functions.sql
index 35d738d576..2546912436 100644
--- a/src/backend/catalog/system_functions.sql
+++ b/src/backend/catalog/system_functions.sql
@@ -621,6 +621,13 @@ LANGUAGE internal
 STRICT IMMUTABLE PARALLEL SAFE
 AS 'unicode_is_normalized';
 
+CREATE OR REPLACE FUNCTION
+  pg_stat_reset_slru(target text DEFAULT NULL)
+RETURNS void
+LANGUAGE INTERNAL
+CALLED ON NULL INPUT VOLATILE PARALLEL SAFE
+AS 'pg_stat_reset_slru';
+
 --
 -- The default permissions for functions mean that anyone can execute them.
 -- A number of functions shouldn't be executable by just anyone, but rather
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 4af16a0f81..7999da77f4 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -5896,7 +5896,8 @@
 { oid => '2307',
   descr => 'statistics: reset collected statistics for a single SLRU',
   proname => 'pg_stat_reset_slru', proisstrict => 'f', provolatile => 'v',
-  prorettype => 'void', proargtypes => 'text', prosrc => 'pg_stat_reset_slru' },
+  prorettype => 'void', proargtypes => 'text', proargnames => '{target}',
+  prosrc => 'pg_stat_reset_slru' },
 { oid => '6170',
   descr => 'statistics: reset collected statistics for a single replication slot',
   proname => 'pg_stat_reset_replication_slot', proisstrict => 'f',
diff --git a/src/test/regress/expected/stats.out b/src/test/regress/expected/stats.out
index 494cef07d3..3355adb956 100644
--- a/src/test/regress/expected/stats.out
+++ b/src/test/regress/expected/stats.out
@@ -882,7 +882,7 @@ SELECT stats_reset > :'slru_commit_ts_reset_ts'::timestamptz FROM pg_stat_slru W
 
 SELECT stats_reset AS slru_commit_ts_reset_ts FROM pg_stat_slru WHERE name = 'CommitTs' \gset
 -- Test that multiple SLRUs are reset when no specific SLRU provided to reset function
-SELECT pg_stat_reset_slru(NULL);
+SELECT pg_stat_reset_slru();
  pg_stat_reset_slru 
 --------------------
  
diff --git a/src/test/regress/sql/stats.sql b/src/test/regress/sql/stats.sql
index 7ae8b8a276..f8fc38eea7 100644
--- a/src/test/regress/sql/stats.sql
+++ b/src/test/regress/sql/stats.sql
@@ -454,7 +454,7 @@ SELECT stats_reset > :'slru_commit_ts_reset_ts'::timestamptz FROM pg_stat_slru W
 SELECT stats_reset AS slru_commit_ts_reset_ts FROM pg_stat_slru WHERE name = 'CommitTs' \gset
 
 -- Test that multiple SLRUs are reset when no specific SLRU provided to reset function
-SELECT pg_stat_reset_slru(NULL);
+SELECT pg_stat_reset_slru();
 SELECT stats_reset > :'slru_commit_ts_reset_ts'::timestamptz FROM pg_stat_slru WHERE name = 'CommitTs';
 SELECT stats_reset > :'slru_notify_reset_ts'::timestamptz FROM pg_stat_slru WHERE name = 'Notify';
 
-- 
2.34.1