> On 12/07/2010 01:22 AM, Tom Lane wrote:
>> Josh Berkus <josh@agliodbs.com> writes:
>>>> However, if you were doing something like parallel pg_dump you could
>>>> just run the parent and child instances all against the slave, so the
>>>> pg_dump scenario doesn't seem to offer much of a supporting use-case for
>>>> worrying about this. When would you really need to be able to do it?
>>
>>> If you had several standbys, you could distribute the work of the
>>> pg_dump among them. This would be a huge speedup for a large database,
>>> potentially, thanks to parallelization of I/O and network. Imagine
>>> doing a pg_dump of a 300GB database in 10min.
>>
>> That does sound kind of attractive. But to do that I think we'd have to
>> go with the pass-the-snapshot-through-the-client approach. Shipping
>> internal snapshot files through the WAL stream doesn't seem attractive
>> to me.
>
> this kind of functionality would also be very useful/interesting for
> connection poolers/loadbalancers that are trying to distribute load
> across multiple hosts and could use that to at least give some sort of
> consistency guarantee.
In addition to this, that will greatly help query based replication
tools such as pgpool-II. Sounds great.
--
Tatsuo Ishii
SRA OSS, Inc. Japan
English: http://www.sraoss.co.jp/index_en.php
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