Dave Crooke <dcrooke(at)gmail(dot)com> wrote:
> I'm not defending the decision to store blobs in a database (it was
> taken a while ago, before the need for frequent updates of the XML)
> and it isn't something that can be readily changed at short notice,
> so please no advice about "don't do that" :-)
I wouldn't sweat 50kB chunks of XML. We store 10MB PDF files. :-)
> is showing 40-50% dead tuples. However, if I disconnect the app, all
> the dead tuples clean up and moved to the "free space" category.
As you suspected, that sounds like lingering database transactions.
Try looking at the pg_stat_activity table for transactions "IDLE in
transaction". If you're having trouble pinning down the cause, look
the pg_locks view to see what tables they've been in.
-Kevin