Latency analysis

Most of the time, you can think of latency--the time taken to process a single transaction--as the inverse of transactions/second. However, worst-case latency is an extremely important number to note for many applications, and you cannot determine it from any average measurement of TPS.

Accordingly, pgbench-tools always saves the latency data pgbench can produce, and it computes average, worst-case, and the 90th percentile of latency results in the HTML results it generates. This data, and the graphs that go along with it, are a major reason to use this toolset instead of running pgbench manually. If you're lucky, your results will look like this, a TPS over time graph from one of the fastest TPC-B-like individual runs in ...

Get PostgreSQL 9.6 High Performance now with O’Reilly online learning.

O’Reilly members experience live online training, plus books, videos, and digital content from 200+ publishers.