Austin Gonyou wrote:
> On Wed, 2003-11-12 at 01:00, Shridhar Daithankar wrote:
>
>>Austin Gonyou wrote:
>>
>>
>>>What facilities are/will be available for hot(online) backups with the
>>>7.4 release? PITR, something else? TIA.
>>
>>pg_dump?
>>
>>Did you mean hot failover or hot backup? Postgresql does hot backup for a long time.
>
>
> I was referring primarly to hot backup. We're migrating from Oracle to
> pgsql, and we wanted to know more about this. From our current
> understanding, pgsql's hot backup is more of an export, than say, a hot
> backup with redo-logs type mode.(i.e. oracle rman). Is there a similar
> utility? I didn't think that pg_dump did that functionality as an actual
> "backup". i.e. keeps track of block changes while IO is going on and
> ensures stuff in process gets backed up as well.
pg_dump takes a snapshot while it starts and it saves the snapshot consistently.
Any ongoing transactions that are not yet committed are not visible to pg_dump
anyways.
Furthermore since the snapshot is consistent, pg_dump does not need redo logs etc.
You can look into asynchronous replications if you want incremental backup.
There is a gborg page for replication projects,
http://gborg.postgresql.org/project/pgreplication/projdisplay.php
pg_dump can be selective but I don't think it can be incremental.
I hope I got your point correctly.
HTH
Shridhar