On 03/05/17 23:24, Merlin Moncure wrote: > On Wed, May 3, 2017 at 12:33 PM, Alvaro Herrera > <alvhe...@2ndquadrant.com> wrote: >> David Fetter wrote: >> >>> When we add a "temporary" GUC, we're taking on a gigantic burden. >>> Either we support it forever somehow, or we put it on a deprecation >>> schedule immediately and expect to be answering questions about it for >>> years after it's been removed. >>> >>> -1 for the GUC. >> >> Absolutely. >> >> So ISTM we have three choices: >> >> 1) we switch unmarked CTEs as inlineable by default in pg11. What seems >> likely to happen for a user that upgrades to pg11 is that 5 out of 10 >> CTE-using queries are going to become faster than with pg10, and they >> are going to be happy; 4 out of five are going to see no difference, but >> they didn't have to do anything about it; and the remaining query is >> going to become slower, either indistinguishably so (in which case they >> don't care and they remain happy because of the other improvements) or >> notably so, in which case they can easily figure where to add the >> MATERIALIZED option and regain the original performance. > > +1 for option 1. This change will be welcome for a large number of > queries, but forced materialization is a real need and I use it often. > This comes off as a very reasonable compromise in my opinion unless it > requires major coding gymnastics to implement. >
+1 to this -- Petr Jelinek http://www.2ndQuadrant.com/ PostgreSQL Development, 24x7 Support, 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
