On Wed, Mar 4, 2020 at 10:43 PM Mark Dilger <mark.dil...@enterprisedb.com> wrote: > The two main differences are that > > (1) This implementation is based on commandtags as enums, not strings and > (2) This implementation uses techniques to reduce lock contention > > I think (2) is the more important part.
My spidey sense is tingling here, telling me that we need some actual benchmarking. Like, suppose we test the two patches under normal cases and under cases that are constructed to be as bad as possible for each of them. Or suppose we test this patch with the lock mitigation strategies and then remove the mitigations for some inexpensive command (e.g. SHOW) and then use pgbench to spam that command. Like you, I suspect that the locking mitigations are important in some workloads, but it would be good to have some figures to back that out, as well as to find out whether there's still too much overhead. -- Robert Haas EnterpriseDB: http://www.enterprisedb.com The Enterprise PostgreSQL Company
