added postgres_query_times_pre_95.sql

sql/postgres_query_times_pre_95.sql

@@ -0,0 +1,36 @@
+--
+--  Author: Hari Sekhon
+--  Date: 2020-08-05 16:16:21 +0100 (Wed, 05 Aug 2020)
+--
+--  vim:ts=2:sts=2:sw=2:et:filetype=sql
+--
+--  https://github.com/harisekhon/bash-tools
+--
+--  License: see accompanying Hari Sekhon LICENSE file
+--
+--  If you're using my code you're welcome to connect with me on LinkedIn and optionally send me feedback to help steer this or other code I publish
+--
+--  https://www.linkedin.com/in/harisekhon
+--
+
+-- PostgreSQL query times from pg_stat_statement for PostgreSQL <= 9.4
+
+-- postgresql.conf needs before start:
+-- shared_preload_libraries = 'pg_stat_statements'
+--
+CREATE extension pg_stat_statements;
+
+SELECT
+  calls,
+  rows,
+  ROUND((total_time / 1000)::numeric, 4) AS total_secs,
+  -- newer versions of PostgreSQL have mean_time field, but we have to calculate on PostgreSQL <= 9.4
+  ROUND((total_time / 1000 / calls)::numeric, 4) AS average_secs,
+  query
+FROM
+  pg_stat_statements
+ORDER BY
+  average_secs DESC,
+  calls DESC,
+  rows DESC
+LIMIT 100;