PostgreSQL 11 Administration Cookbook

How it works…

The PostgreSQL statistics accumulate various pieces of useful information. These statistics can be reset to zero using an administrator function. Also, as the data accumulates over time, we usually find that objects that have been there for longer periods of time have higher apparent usage. So, if we see a low number for idx_scan, then it might be that the index was newly created (as was the case in my preceding demonstration), or that the index is only used by a part of the application that runs only at certain times of the day, week, month, and so on.

Another important consideration is that the index may be a unique constraint index that exists specifically to safeguard against duplicate INSERT commands. An INSERT operation ...