On Sat, 2009-01-10 at 09:40 +0000, Simon Riggs wrote: > This leads to an error when we SubTransSetParent(child_xid, top_xid); > since this assumes that the top_xid is the parent, which it is not. > Mostly you wouldn't notice unless you were looking up the subtrans > status for an xid that had committed but was the child of an aborted > subtransaction, with the top level xid having > 64 subtransactions. > It's possible the confusion leads to other bugs in UnobservedXid > processing, but I didn't look too hard at that. > > AFAICS we need both parent and top xids.
I wonder if its possible to derive the parent by looking at the highest/most newly assigned xid? Abort records would remove aborted subtransactions and AFAIK we currently assign a new subtransaction only ever from the latest current subtransaction. (This wouldn't be necessarily true if supported true branch-anywhere subtransactions, but we don't). Sounds correct, but not really sure. -- Simon Riggs www.2ndQuadrant.com PostgreSQL Training, Services and Support -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
