The Database Chronicles

This post is not about troubleshooting but rather about an interesting observation.

One common performance issue in Linux systems is a program consuming unexpectedly high CPU.

When diagnosing a performance problem, interpreting the flow inside of the application is as important as other aspects of the whole process, such as tools and methodology.

Lightweight locks (LWLocks) are a type of interprocess lock used by PostgreSQL to coordinate simultaneous access of multiple processes to a shared memory region.

It all started with a performance issue in one of our clusters.

Here are some six ways that can be used to force a query go with sequential scan access method in PostgresSQL.

Here is a quick and interesting observation regarding the %logons% statistics.

The quickest and simplest way of ensuring what has been populated in In-Memory column store (IMCS) is to query the V$IM_SEGMENTS view.

The following is a (short and quick) scenario I recently faced when analyzing a parallel query and its response time.

I will not pretend that the idea presented in this post is aimed at addressing a number of troubleshooting scenarios but in some cases it may come in handy.