created: 20190616221128760
creator: vplesnila
modified: 20190616221559458
modifier: vplesnila
tags: PostgreSQL
title: PostgreSQL - pgSentinel
type: text/vnd.tiddlywiki

! Parameteres for pg_stat_statements
```
shared_preload_libraries = 'pg_stat_statements'

pg_stat_statements.max = 10000
pg_stat_statements.track = all
```

! Parameteres for pg_sentinel
```
shared_preload_libraries = 'pg_stat_statements,pgsentinel'
# Icncrease the max size of the query strings Postgres records
track_activity_query_size = 2048
# Track statements generated by stored procedures as well
pg_stat_statements.track = all
```

! Create the extensions at the DATABASE level

```
create extension pg_stat_statements;
create extension pgsentinel;
```

! Performance views
* `pg_stat_activity`
* `pg_stat_statements`
* `pg_active_session_history` (history of `pg_stat_activity`)

! Examples

```
select ash_time,top_level_query,query,queryid,wait_event_type,wait_event from pg_active_session_history where query != 'ROLLBACK' order by ash_time desc limit 15;

select ash_time, wait_event, wait_event_type from pg_active_session_history where queryid=3548524963606505593 order by ash_time desc limit 15; 
```