Understanding memory units in PostgreSQL

In this recipe, we will be discussing the memory components of PostgreSQL instances.

Getting ready

PostgreSQL uses several memory components for each unique usage. That is, it uses dedicated memory areas for transactions, sort/join operations, maintenance operations, and so on. If the configured memory component doesn't fit the usage of the live application, then we may hit a performance issue, where PostgreSQL tries for more I/O.

How to do it...

Let us discuss about, how to tune the major PostgreSQL memory components:

shared_buffers

This is the major memory area that PostgreSQL uses for executing the transactions. On most Linux operating systems, it is recommended to allocate at least 25% of RAM as shared buffers, by leaving 75% of RAM to OS, OS cache, and for other PostgreSQL memory components. PostgreSQL provide multiple ways to create these shared buffers. The supported shared memory creation techniques are POSIX shared memory, System V shared memory...