Re: Simplifying replication

On Tue, Oct 26, 2010 at 9:59 PM, Josh Berkus <josh@agliodbs.com> wrote:
>
>> If you set wal_keep_segments=0, archive_mode=on, and
>> archive_command=<something>, you might run out of disk space.
>>
>> If you set wal_keep_segments=-1, you might run out of disk space.
>>
>> Are you any more screwed in the second case than you are in the first
>> case?
>
> It is the same to the user either way.  In either case you have to
> change some settings and restart the master.

Except that changing wal_keep_segments doesn't require restarting the master.

The point of allowing -1 was to allow someone to set it to that value
temporarily, to be able to do a hot backup without having to guess how
large to set it.  If you don't have enough disk space for a backup to
complete, you're kind of hosed either way.

--
Robert Haas
EnterpriseDB: http://www.enterprisedb.com
The Enterprise PostgreSQL Company