On Tue, Feb 08, 2022 at 04:43:47PM -0800, Andres Freund wrote: > On 2022-02-08 22:13:01 +0100, Tomas Vondra wrote: > > On 10/24/21 03:40, Noah Misch wrote: > > > Avoid race in RelationBuildDesc() affecting CREATE INDEX CONCURRENTLY. > > > > > > CIC and REINDEX CONCURRENTLY assume backends see their catalog changes > > > no later than each backend's next transaction start. That failed to > > > hold when a backend absorbed a relevant invalidation in the middle of > > > running RelationBuildDesc() on the CIC index. Queries that use the > > > resulting index can silently fail to find rows. Fix this for future > > > index builds by making RelationBuildDesc() loop until it finishes > > > without accepting a relevant invalidation. It may be necessary to > > > reindex to recover from past occurrences; REINDEX CONCURRENTLY suffices. > > > Back-patch to 9.6 (all supported versions). > > > > > > Noah Misch and Andrey Borodin, reviewed (in earlier versions) by Andres > > > Freund. > > > > > > Discussion: https://postgr.es/m/20210730022548.ga1940...@gust.leadboat.com > > > > > > > Unfortunately, this seems to have broken CLOBBER_CACHE_ALWAYS builds. Since > > this commit, initdb never completes due to infinite retrying over and over > > (on the first RelationBuildDesc call).
Thanks for the report. I had added the debug_discard arguments of InvalidateSystemCachesExtended() and RelationCacheInvalidate() to make the new code survive a CREATE TABLE at debug_discard_caches=5. Apparently that's not enough for initdb. I'll queue a task to look at it. It's a good reminder to set wait_timeout on buildfarm animals. (I should take that advice, too.) > Ugh. Do we need to do something about WRT the next set of minor releases? No, given that this code already debuted in the November releases.
