Re: Dubious shortcut in ckpt_buforder_comparator()

2018-01-10 Thread Tom Lane
Andres Freund writes: > On 2018-01-10 13:06:50 -0500, Tom Lane wrote: >> So I think we should get rid of that micro-optimization, which is >> probably useless anyway from a performance standpoint, and do the >> comparison honestly. Any objections? > No, absolutely none. You're going to change it

Re: Dubious shortcut in ckpt_buforder_comparator()

2018-01-10 Thread Andres Freund
Hi, On 2018-01-10 13:06:50 -0500, Tom Lane wrote: > So I think we should get rid of that micro-optimization, which is > probably useless anyway from a performance standpoint, and do the > comparison honestly. Any objections? No, absolutely none. You're going to change it? Greetings, Andres Fre

Dubious shortcut in ckpt_buforder_comparator()

2018-01-10 Thread Tom Lane
While analyzing a recent crash report[1], I noticed that bufmgr.c's ckpt_buforder_comparator is coded to assume that no two CkptSortItems could have equal page IDs; it therefore skips the final comparison and will never return 0 (equal). I do not think that assumption is correct. I do not see any