On 06/26/2013 07:05 AM, Jamie Martin wrote: > FYI I submitted a slightly modified patch since Amit's measurements that is > slightly faster.
Yes. My perspective is that this is a worthwhile optimization for a minority, but fairly well-known, use case, provided that it doesn't negatively impact any other, more common use case. Potential cases where I can see negative impact are: A) normal table with a few, mostly non-null columns (recent pgbench testing seems to have validated no measurable impact). B) table with many (400+) mostly non-null columns C) table with many (400+) mostly null columns, where column #390 was null and gets updated to a not null value I don't *think* that Jamie's performance tests have really addressed the above cases. However, do people agree that if performance on the patch passes for all of A, B and C, then it's OK to apply? -- 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
