Hi Daniil On 10/04/2026 09:10, Daniil Davydov wrote: > Having both checks might look a bit redundant since the read stream will > eventually call the StartReadBuffersImpl function. On the other hand, there > are > many places which are checking this restriction even if subsequent functions > (from bufmgr) also have this check. > > So, I'll keep both checks and a bit reduce the comments in the bufmgr.c .
Putting this check a level deeper sounds good to me. > BTW, what do you think about making this comment less "concrete"? : > # SELECT via index scan from other session. > # Sequential scans are blocked at read_stream_begin_relation(); index scans > # bypass that path entirely and reach ReadBufferExtended() in bufmgr.c > # (nbtree's _bt_getbuf calls ReadBuffer directly for individual page fetches). > # enable_seqscan=off forces the planner to use the index. > > I mean that if the described logic changes, this comment will become > confusing. > We can describe the test in general words. For example : > # Index scans can use a different code path from the one sequential scans are > # following. Make sure that we cannot access other sessions' temp tables > during > # index scan either. +1 Yeah, it's indeed too verbose. I guess these comments were originally just for me so I wouldn't get too confused along the way :) I don't have anything else to add at this point. Unless there are any objections, I'll mark the CF entry as 'Ready for Committer.' Thanks! Best, Jim
