Re: [PATCHES] Doc update for pg_start_backup

Heikki Linnakangas <heikki@enterprisedb.com> writes:
> Added a note to the docs that pg_start_backup can take a long time to 
> finish now that we spread out checkpoints:

I was starting to wordsmith this, and then wondered whether it's not
just a stupid idea for pg_start_backup to act that way.  The reason
you're doing it is to take a base backup, right?  What are you going
to take the base backup with?  I do not offhand know of any backup
tools that don't suck major amounts of I/O bandwidth.  That being
the case, you're simply not going to schedule the operation during
full-load periods.  And that leads to the conclusion that
pg_start_backup should just use CHECKPOINT_IMMEDIATE and not slow
you down.

Thoughts?
        regards, tom lane