> Next question is what people think about back-patching into 9.2 so as > to eliminate the performance regression vs 9.1. I believe this would > be safe (although some care would have to be taken to put the added > boolean fields into places where they'd not result in an ABI break). > However it may not be worth the risk. The 40% slowdown seen with > Pavel's example seems to me to be an extreme corner case --- Dong's > result of 8% slowdown is probably more realistic for normal uses > of SPI_execute. Might be better to just live with it in 9.2. > Thoughts?
8% is a pretty serious regression, for those of us with applications which do a lot of dynamic SQL. As a reminder, many people do dynamic SQL even in repetitive, performance-sensitive functions in order to avoid plan caching. Also partition-handlers often use dynamic SQL, and a 10% drop in loading rows/second would be a big deal. Let's put it this way: if the community doesn't backport it, we'll end up doing so ad-hoc for some of our customers. -- Josh Berkus PostgreSQL Experts Inc. http://pgexperts.com -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
