> I think it's pretty well explained in the fine manual.
>
> http://www.postgresql.org/docs/current/static/runtime-config-wal.html#GUC-WAL-KEEP-SEGMENTS
Nope. No relationship to checkpoint_segments is explained there. Try
again?
>> If checkpoint_segments were a hard limit, then we could let admins set
>> wal_keep_segments to -1, knowing that they'd set checkpoint_segments to
>> the max space they had available.
>
> This assumes that more checkpoint segments is always better, which
> isn't true. I might have 100 GB of disk space free, but not want to
> replay WAL for 4 days if I have a crash.
No, it assumes no such thing.
-- -- Josh Berkus PostgreSQL Experts Inc.
http://www.pgexperts.com