On 2020-Mar-25, Andres Freund wrote:
> What I was thinking of was a new flag, with a distinct value from
> PROC_IN_VACUUM. It'd currently just be specified in the
> GetCurrentVirtualXIDs() calls in WaitForOlderSnapshots(). That'd avoid
> needing to wait for other CICs on different relations. Since CIC is not
> permitted on system tables, and CIC doesn't do DML on normal tables, it
> seems fairly obviously correct to exclude other CICs.
Hmm, that does work, and seems a pretty small patch -- attached. Of
course, some more commentary is necessary, but the theory of operation
is as Andres says. (It does not solve the vacuuming problem I was
describing in the other thread, only the spurious waiting that James is
complaining about in this thread.)
I'm going to try and poke holes on this now ... (Expression indexes with
falsely immutable functions?)
--
Álvaro Herrera https://www.2ndQuadrant.com/
PostgreSQL Development, 24x7 Support, Remote DBA, Training & Services
