On 8/6/15 12:49 PM, Kevin Grittner wrote:
>> 2) If a WAL segment is in fact required for the backed up DB to
>> > start, why would pg_basebackup not include those by default? To
>> > not do so, doesn't create a backup file, just in this case, a
>> > tarball that's worthless.
> ... unless you are archiving the WAL to somewhere that it will be
> kept long enough to be usable for such purposes. If you are (and I
> highly recommend that you do so), including WAL in the base backup
> is a waste of both bandwidth and storage space.
This is arguably an artifact of the evolution of replication in
PostgreSQL. You used to do tar backup + archiving, then you could
switch to pg_basebackup + archiving, and nowadays you could switch to
pg_basebackup without archiving, but the default behavior of
pg_basebackup still caters to the old case.