> On Mon, Nov 30, 2020 at 04:54:39PM -0300, Alvaro Herrera wrote: > > In a previous thread [1], we added smarts so that processes running > CREATE INDEX CONCURRENTLY would not wait for each other. > > One is adding the same to REINDEX CONCURRENTLY. I've attached patch > 0002 here which does that. > > Why 0002, you ask? That's because preparatory patch 0001 simplifies the > ReindexRelationConcurrently somewhat by adding a struct to be used of > indexes that are going to be processed, instead of just a list of Oids. > This is a good change in itself because it let us get rid of duplicative > open/close of the index rels in order to obtain some info that's already > known at the start.
Thanks! The patch looks pretty good to me, after reading it I only have a few minor comments/questions: * ReindexIndexInfo sounds a bit weird for me because of the repeating part, although I see there is already a similar ReindexIndexCallbackState so probably it's fine. * This one is mostly for me to understand. There are couple of places with a commentary that 'PROC_IN_SAFE_IC is not necessary, because the transaction only takes a snapshot to do some catalog manipulation'. But for some of them I don't immediately see in the relevant code anything related to snapshots. E.g. one in DefineIndex is followed by WaitForOlderSnapshots (which seems to only do waiting, not taking a snapshot), index_set_state_flags and CacheInvalidateRelcacheByRelid. Is taking a snapshot hidden somewhere there inside?
