Merge pull request #278936 from varun-dhawan/varund-jul

[PostgreSQL] doc corrections

Author: denrea

articles/postgresql/flexible-server/how-to-optimize-query-stats-collection.md

@@ -3,8 +3,7 @@ title: Optimize query stats collection
 description: This article describes how you can optimize query stats collection on Azure Database for PostgreSQL - Flexible Server.
 author: assaff
 ms.author: assaff
-ms.reviewer: maghan
-ms.date: 04/27/2024
+ms.date: 06/21/2024
 ms.service: postgresql
 ms.subservice: flexible-server
 ms.topic: how-to
@@ -14,18 +13,21 @@ ms.topic: how-to
 
 [!INCLUDE [applies-to-postgresql-flexible-server](~/reusable-content/ce-skilling/azure/includes/postgresql/includes/applies-to-postgresql-flexible-server.md)]
 
-This article describes how to optimize query statistics collection on an Azure Database for PostgreSQL flexible server instance.
+This article describes how to optimize query statistics collection on an Azure Database for PostgreSQL flexible server using pg_stat_statements extension
 
 ## Use pg_stat_statements
 
 **Pg_stat_statements** is a PostgreSQL extension that can be enabled in Azure Database for PostgreSQL flexible server. The extension provides a means to track execution statistics for all SQL statements executed by a server. This module hooks into every query execution and comes with a non-trivial performance cost. Enabling **pg_stat_statements** forces query text writes to files on disk.
 
-If you have unique queries with long query text or you don't actively monitor **pg_stat_statements**, disable **pg_stat_statements** for best performance. To do so, change the setting to `pg_stat_statements.track = NONE`.
+> [!NOTE]  
+> `pg_stat_statements.track` is by default to NONE (i.e. disabled).
 
-To set `pg_stat_statements.track = NONE`:
+If you want to start tracking the execution statistics of all SQL statements executed by a server, then enable **pg_stat_statements**. To do so, set the value to `TOP` or `ALL`, depending on whether you want to track top-level queries or also nested queries (those executed inside a function or procedure).
+
+To set **pg_stat_statements.track** = `TOP`
 
 - In the Azure portal, go to the [Azure Database for PostgreSQL flexible server resource management page and select the server parameters blade](concepts-server-parameters.md).
-- Use the [Azure CLI](connect-azure-cli.md) az postgres server configuration set to `--name pg_stat_statements.track --resource-group myresourcegroup --server mydemoserver --value NONE`.
+- Use the [Azure CLI](connect-azure-cli.md) az postgres server configuration set to `--name pg_stat_statements.track --resource-group myresourcegroup --server mydemoserver --value TOP`.
 
 ## Use the Query Store