Running pgbench manually

As a simple example of running a test, you could execute the SELECT only test for a small number of transactions. Here's a quick test from the sample server:

$ pgbench -S -c 4 -t 20000 pgbench
starting vacuum...end.
transaction type: SELECT only
scaling factor: 10
query mode: simple
number of clients: 4
number of threads: 1
number of transactions per client: 20000
number of transactions actually processed: 80000/80000
tps = 17070.599733 (including connections establishing)
tps = 17173.602799 (excluding connections establishing)

This is simulating the situation where four database clients are all active at the same time and continuously asking for data. Each client runs until it executes the requested number of transactions.

Since this is a Linux system, the pgbench driver program itself is known to limit performance here when run as a single thread, described in more detail below. Using more threads (only available in PostgreSQL 9.0 and later) shows a...