Mastering PostgreSQL 9.6

Using pg_stat_statements

After discussing the first couple of views, it is time to turn our attention to one of the most important views, which can be used to spot performance problems. I am of course speaking about pg_stat_statements. The idea is to have information about queries on your system. It helps to figure out which types of queries are slow and how often queries are called.

To use the module, three steps are necessary:

1. Add pg_stat_statements to shared_preload_libraries in the postgresql.conf file.
2. Restart the database server.
3. Run CREATE EXTENSION pg_stat_statements in the database(s) of your choice.

Let's inspect the definition of the view:

test=# \d pg_stat_statements            View "public.pg_stat_statements"  Column | Type | Modifiers ...