On Fri, Dec 26, 2008 at 02:17:29PM -0500, Tom Lane wrote: > So the alternatives I see are: > > 1. Go back to Hitoshi's plan of passing WindowAggState to the > aggregates. This will require changing every one of the ten aggregates > in the core distro, as well as every third-party aggregate that has > a similar optimization; and we just have to keep our fingers crossed > that anyone who's taking a short-cut will fix their code before it > fails in the field. > > 2. Use an intermediate dummy AggState as I have in my version, but > document some convention for telling this from a "real" AggState > when needed. (Not hard, we just pick some field that would never be > zero in a real AggState and document testing that.) This is certainly > on the ugly side, but it would very substantially cut the number of > places that need changes. Only aggregates that are doing something > irreversible in their final-functions would need to be touched. > > If we were working in a green field then #1 would clearly be the > preferable choice, but worrying about compatibility with existing > third-party aggregates is making me lean to #2. Comments?
Exactly how large is this third-party aggregate problem? Rather than support a huge wart, we could just tell people starting now and prominently in the release notes that such things need a re-do and point to examples of how it's done. The case this won't work for is where a vendor of a proprietary C extension is gone and/or won't update their stuff for 8.4, and it seems to me that we can't, and shouldn't try to, take responsibility for that use case anyhow. Cheers, David. -- David Fetter <da...@fetter.org> http://fetter.org/ Phone: +1 415 235 3778 AIM: dfetter666 Yahoo!: dfetter Skype: davidfetter XMPP: david.fet...@gmail.com Remember to vote! Consider donating to Postgres: http://www.postgresql.org/about/donate -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
