Explain how to enable query stats

[manuelmeurer]

Great gem! 👏

I installed it and it told me query stats are not enabled and, upon trying to enable them, "The database user does not have permission to enable query stats"
Could you quickly explain in the README what the query stats are and how to enable them? Are they same as the Statistics Collector?
A bit more info would be great for Postgres newbies like me.

Also, it might make sense to mention in the README that the performance of the app is not affected by enabling PGHero (I assume it's not 😄).

[tmikoss]

Here's how you enable query stat statements - http://www.postgresql.org/docs/9.3/static/pgstatstatements.html

As for performance impact, postgres docs state that enabling pg_stat_statements will require additional memory for database.

[fbandrey]

@manuelmeurer you may enable it manually (under "postgres" user, for example) by running:

CREATE extension pg_stat_statements;

I wrote a short wiki here: https://github.com/ankane/pghero/wiki/How-to-manually-enable-query-stats

[manuelmeurer]

Thanks guys! I'll try to get it running and prepare a PR for the README since I think this should be mentioned there.