Re: BUG #5946: Long exclusive lock taken by vacuum (not full)

Greg Stark <gsstark@mit.edu> writes:
> So is it ok for inserting one row to cause my table to grow by 90GB?
> Or should there be some maximum size increment at which it stops
> growing? What should that maximum be? What if I'm on a big raid system
> where that size doesn't even add a block to every stripe element?

I'd think that capping the idea to the segment size makes sense.

Also, what about having a background process (bgwriter or autovacuum
come to mind) doing the work, rather than the backend that happens to be
inserting the row?

It could send a message, and continue creating a newer 8kb block if the
background process has not yet extended the storage.  Also, to be safe I
guess we could arrange to have the new segment be created way before
reaching the very end of the relation (so that adding 8kb does not need
to create a new segment, so as to avoid a race condition with the
background process doing so itself).

Regards,
--
Dimitri Fontaine
http://2ndQuadrant.fr     PostgreSQL : Expertise, Formation et Support