"Anjan Dave" <[EMAIL PROTECTED]> writes: > -bash-3.00$ time pgbench -c 1000 -t 30 pgbench > starting vacuum...end. > transaction type: TPC-B (sort of) > scaling factor: 1 > number of clients: 1000 > number of transactions per client: 30 > number of transactions actually processed: 30000/30000 > tps = 45.871234 (including connections establishing) > tps = 46.092629 (excluding connections establishing)
I can hardly think of a worse way to run pgbench :-(. These numbers are about meaningless, for two reasons: 1. You don't want number of clients (-c) much higher than scaling factor (-s in the initialization step). The number of rows in the "branches" table will equal -s, and since every transaction updates one randomly-chosen "branches" row, you will be measuring mostly row-update contention overhead if there's more concurrent transactions than there are rows. In the case -s 1, which is what you've got here, there is no actual concurrency at all --- all the transactions stack up on the single branches row. 2. Running a small number of transactions per client means that startup/shutdown transients overwhelm the steady-state data. You should probably run at least a thousand transactions per client if you want repeatable numbers. Try something like "-s 10 -c 10 -t 3000" to get numbers reflecting test conditions more like what the TPC council had in mind when they designed this benchmark. I tend to repeat such a test 3 times to see if the numbers are repeatable, and quote the middle TPS number as long as they're not too far apart. regards, tom lane ---------------------------(end of broadcast)--------------------------- TIP 2: Don't 'kill -9' the postmaster