Simon Riggs <si...@2ndquadrant.com> wrote: > On 8 June 2013 22:25, Kevin Grittner <kgri...@ymail.com> wrote: >> Simon Riggs <si...@2ndquadrant.com> wrote:
> There are also difficulties in semantics, since when > we have OLD and NEW at row level we know we are discussing the same > row. With sets of OLD and NEW we'd need to be able to link the > relations back together somehow, which couldn't be done by PK since > that could change. So we'd need to invent some semantics for a > "linking identifier" of some description. Which once we've done it > would be used by people to join them back together again, which is > what we already had in the first place. So my take is that it sounds > expressive, but definitely not performant. I have used a feature like this in other database products, and can say from experience that these relations in a statement trigger can be very useful without the linkage you propose. I can see how the linkage could potentially be useful, but if that is the only hang-up, we would be adding a powerful feature without it. > Since my objective is performance, not standards, I don't see a reason > to work on that, yet. I might have time to work on it later, lets see. This seems like it has some overlap with the delta relations I will need to generate for incremental maintenance of materialized views, so we should coordinate on those efforts if they happen to occur around the same time. -- Kevin Grittner EnterpriseDB: http://www.enterprisedb.com The Enterprise PostgreSQL Company -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
