pghero on PostgresApp pg_stat_statements must be loaded via shared_preload_libraries

You have to restart the Postgresql Server in order to load the shared library and afterwards execute

CREATE EXTENSION pg_stat_statements;

in the database you want to monitor.

Additionally you will have to edit the following line in postgresql.conf

shared_preload_libraries = ''

shared_preload_libraries = 'pg_stat_statements'

A restart of the PSQL service is required.

postgresql rails-postgresql

Create extension by executing following query

CREATE EXTENSION pg_stat_statements

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