On Wed, Sep 27, 2017 at 1:40 PM, Andres Freund <and...@anarazel.de> wrote: > I don't think you can even measure the overhead of building the > table. This is inserting ~8k rows in an accurately sized hashtable - a > vanishingly small amount of time in comparison to the backend startup > time (and even more so postmaster startup). My measurement shows it > takes about 0.4 ms to build (gdb in, query, reset oid2builtins = 0, > query - repeat a couple times).
0.4ms isn't negligible as a fraction of backend startup time, is it? I think backend startup time is a few milliseconds. $ echo '\set x 1' > x.txt $ pgbench -n -C -c 1 -f x.txt -T 10 transaction type: x.txt scaling factor: 1 query mode: simple number of clients: 1 number of threads: 1 duration: 10 s number of transactions actually processed: 5091 latency average = 1.965 ms tps = 508.866931 (including connections establishing) tps = 12909.303693 (excluding connections establishing) -- Robert Haas EnterpriseDB: http://www.enterprisedb.com The Enterprise PostgreSQL Company -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers