Re: For the ametures. (related to "Are we losing momentum?")

Ben Clewett writes:

> I could not work out from the documentation whether it takes a snapshot
> at the start time, or archives data at the time it find's it.  The
> documentation (app-pg-dump.html).  As the documentation does not clarify
> this very important point, I desided it's not safe to use when the
> system is in use.
>
> Can this command can be used, with users in the system making heavy
> changes, and when takes many hours to complete, does produce a valid and
> consistent backup?

From the pg_dump reference page:
 <para>  <application>pg_dump</application> makes consistent backups even if the  database is being used concurrently.
<application>pg_dump</application> does not block other users accessing the database (readers or  writers). </para>
 

From the chapter Backup and Restore:
 <para>  Dumps created by <application>pg_dump</> are internally consistent,  that is, updates to the database while
<application>pg_dump</>is  running will not be in the dump. <application>pg_dump</> does not  block other operations on
thedatabase while it is working.  (Exceptions are those operations that need to operate with an  exclusive lock, such
as<command>VACUUM FULL</command>.) </para>
 

-- 
Peter Eisentraut   peter_e@gmx.net