What is vacuuming in PostgreSQL?
Description. VACUUM reclaims storage occupied by dead tuples. In normal PostgreSQL operation, tuples that are deleted or obsoleted by an update are not physically removed from their table; they remain present until a VACUUM is done.
What is vacuum analyze?
VACUUM ANALYZE performs a VACUUM and then an ANALYZE for each selected table. This is a handy combination form for routine maintenance scripts. See ANALYZE for more details about its processing. Plain VACUUM (without FULL) simply reclaims space and makes it available for re-use.
What is Pg_stat_all_tables?
The pg_stat_all_tables view shows one row for each table in the current database (including TOAST tables) to display statistics about accesses to that specific table. In Greenplum Database 5, the pg_stat_*_tables views display access statistics for tables only from the master instance. …
What is WALWriteLock?
WALWriteLock: accrued by PostgreSQL processes while WAL records are flushed to disk or during a WAL segments switch. synchronous_commit=off removes the wait for disk flush, full_page_writes=off reduces the amount of data to flush.
Which default role is created automatically with PostgreSQL?
When a new database is created, PostgreSQL by default creates a schema named public and grants access on this schema to a backend role named public . All new users and roles are by default granted this public role, and therefore can create objects in the public schema.
Why is it important to monitor your PostgreSQL database?
Monitoring your PostgreSQL database is not only important to see if you’re having an issue, but also to know if you need to change something to improve your database performance, that is probably one of the most important things to monitor in a database. Let’s see some metrics that are important for this.
How to track changes made to tables in PostgreSQL?
To track those changes made to tables in PostgreSQL you can write yourself a generic changelog trigger. The easiest way to do that is to write a generic PL/pgSQL function and use it for all tables in the system. As PostgreSQL provides good support for stored procedures, this is definitely not hard to do.
How much does it cost to monitor a PostgreSQL server?
Monitoring a typical PostgreSQL server requires one sensor per database instance plus sensors for any other server and OS parameter you may want to monitor. For more than 100 sensors, a license is necessary. Their prices vary according to the number of sensors and start at $1 600 for 500 sensors.
What to look for in PostgreSQL replication issues?
The key metrics to monitor for replication are the lag and the replication state. The most common issues are networking issues, hardware resource issues, or under dimensioning issues. If you are facing a replication issue you will need to know this asap as you will need to fix it to ensure the high availability environment.