High Performance PostgreSQL for Rails

Deciding When to Partition

You might be wondering when to partition. You may also be wondering whether table partitioning is truly required or is more of a nice-to-have. Let’s take a look.

Let’s start with a high-side extreme. PostgreSQL does set limits on most things, including a maximum table size.

At publication time, the maximum table size is 32 TB.^[369]

This means that when inserts or other DML operations are sent to a table that exceeds 32 TB, they’ll fail. While that’s the hard upper limit in PostgreSQL, you’ll likely hit issues well before that, depending on the size of your instance and your concurrent activity.

If hitting that limit sounds unrealistic, consider that there are real-world stories where that happened and caused downtime. ...