Addendum to the FAQ

Hello,

based on a common question, here is an addendum for the FAQ:
https://wiki.postgresql.org/wiki/FAQ

Question: The files in pg_xlog/* take up a lot of disk space, can they be
removed?

Answer:

Under no circumstances must files in the pg_xlog/ directory be removed,
they are essential for the database operation. The files in this directory
store the transaction log, without these files the database can't recover
after a crash or shutdown.

The size of the pg_xlog/ directory can be configured by setting the
"min_wal_size" and "max_wal_size" GUC (PostgreSQL 9.5 and newer), or by
setting the "checkpoint_segments" GUC (9.4 and earlier).
https://www.postgresql.org/docs/current/static/runtime-config-wal.html
https://www.postgresql.org/docs/9.4/static/runtime-config-wal.html

Regards,

--
Andreas 'ads' Scherbaum
German PostgreSQL User Group
European PostgreSQL User Group - Board of Directors
Volunteer Regional Contact, Germany - PostgreSQL Project