Merge pull request #128078 from JaredMSFT/master

clarifying the difference between pg_statistics and pg_stats_* views …

Author: v-dirichards

articles/reliability/reliability-azure-database-postgresql.md

@@ -264,11 +264,11 @@ Application downtime starts after step 1 and continues until step 6 finishes. Th
 
 #### Best practices for PostgreSQL statistics after failover
 
-After a PostgreSQL failover, maintaining optimal database performance involves understanding the distinct roles of [pg_statistic](https://www.postgresql.org/docs/current/catalog-pg-statistic.html) and the [pg_stat_*](https://www.postgresql.org/docs/current/monitoring-stats.html) tables. The `pg_statistic` table stores optimizer statistics, which are crucial for the query planner. These statistics include data distributions within tables and remain intact after a failover, ensuring that the query planner can continue to optimize query execution effectively based on accurate, historical data distribution information.
+After a PostgreSQL failover, maintaining optimal database performance involves understanding the distinct roles of [pg_statistic](https://www.postgresql.org/docs/current/catalog-pg-statistic.html) and the [pg_stat_*](https://www.postgresql.org/docs/current/monitoring-stats.html) views. The `pg_statistic` table stores optimizer statistics, which are crucial for the query planner. These statistics include data distributions within tables and remain intact after a failover, ensuring that the query planner can continue to optimize query execution effectively based on accurate, historical data distribution information.
 
-In contrast, the `pg_stat_*` tables, which record activity statistics such as the number of scans, tuples read, and updates, reset upon failover. An example of such a table is `pg_stat_user_tables`, which tracks activity for user-defined tables. This reset accurately reflects the new primary's operational state but also means the loss of historical activity metrics that could inform the autovacuum process and other operational efficiencies.
+In contrast, the `pg_stat_*` views, provide runtime activity statistics such as the number of scans, tuples read, and updates, are stored in memory and reset upon failover. An example is `pg_stat_user_tables`, which tracks activity for user-defined tables. This reset accurately reflects the new primary's operational state but also means the loss of historical activity metrics that could inform the autovacuum process and other operational efficiencies.
 
-Given this distinction, run `ANALYZE` after a PostgreSQL failover. This action updates the `pg_stat_*` tables, like `pg_stat_user_tables`, with fresh activity statistics, helping the autovacuum process and ensuring that the database performance remains optimal in its new role. This proactive step bridges the gap between preserving essential optimizer statistics and refreshing activity metrics to align with the database's current state.
+Given this distinction, you may consider running `ANALYZE` after a PostgreSQL failover. This action updates the `pg_stat_*` data (e.g., `pg_stat_user_tables`) with fresh vacuum activity statistics, helping the autovacuum process, which in turn, ensures that the database performance remains optimal in its new role. This proactive step bridges the gap between preserving essential optimizer statistics and refreshing activity metrics to align with the database's current state.
 
 ### Zone-down experience