Hi, On 2021-03-13 10:05:21 -0800, Andres Freund wrote: > Cool. I'll give it a try.
I have a few questions about the patch: - Why was collect_oids() changed to a different hashtable as part of this change? Seems fairly independent? - What's the point of all those cached_* stuff? There's not a single comment explaining it as far as I can tell... Several of them are never used as a cache! E.g. cached_archiverstats, cached_bgwriterstats, ... - What is the idea behind pgstat_reset_shared_counters() using pgstat_copy_global_stats() to reset, using StatsShmem->*_reset_offset? But then still taking a lock in pgstat_fetch_stat_*? Again, no comments explaining what the goal is. It kinda looks like you tried to make both read and write paths not use the lock, but then ended up using a lock? Do you have some benchmarks that you used to verify performance? I think I'm going to try to split the storage of fixed-size stats in StatsShmemStruct into a separate patch. That's already a pretty large change, and it's pretty much unrelated to the rest. Greetings, Andres Freund
