On Wed, Sep 27, 2017 at 1:40 PM, Andres Freund <andres@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
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