Tom Lane wrote on 24.07.2012 17:55:
Joins on tid columns just aren't supported very well at the moment. Partly that's from lack of round tuits, and partly it's because it doesn't seem all that wise to encourage people to use them. There are gotchas if any of the rows receive concurrent updates.
Thanks for the clarification. I will keep that in mind.
FWIW, it might be helpful to cast this as a NOT EXISTS rather than NOT IN subquery.
Hmm. How would you change that into an NOT EXISTS clause (so that one of the duplicates remains) Everything I come up with is in fact slower than the NOT IN solution. Regards Thomas -- Sent via pgsql-performance mailing list (pgsql-performance@xxxxxxxxxxxxxx) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-performance
