Re: [HACKERS] 6.6 items

ZEUGSWETTER Andreas IZ5 wrote:
> 
> > - Up time. This means hot backup and no locking of the database during
> > vacuum.
> >
> If Vadim made the change to make pg_dump dump in one transaction then
> PostgreSQL already has "hot backup" in 6.5. This will do a consistent
> snapshot of your database as it was when pg_dump began as long as you
> don't change the database layout during the dump.

This is done.

Vacuum doesn't lock entire database. But it acquires access 
exclusive lock over table being vacuumed and so delay all 
(even SELECT) concurrent query executions. Lock released
after table vacuumed.

Vadim