Andres Freund wrote: > I'm looking into three approaches right now: > > 3) Use WAL logging for the already_marked = true case.
> 3) This approach so far seems the best. It's possible to reuse the > xl_heap_lock record (in an afaics backwards compatible manner), and in > most cases the overhead isn't that large. It's of course annoying to > emit more WAL, but it's not that big an overhead compared to extending a > file, or to toasting. It's also by far the simplest fix. I suppose it's fine if we crash midway from emitting this wal record and the actual heap_update one, since the xmax will appear to come from an aborted xid, right? I agree that the overhead is probably negligible, considering that this only happens when toast is invoked. It's probably not as great when the new tuple goes to another page, though. -- Álvaro Herrera http://www.2ndQuadrant.com/ PostgreSQL Development, 24x7 Support, Remote DBA, Training & Services -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
