> For the complete documentation index, see [llms.txt](https://til.notdu.com/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://til.notdu.com/database/intro-to-database-systems/tree-indexes-ii/partial-indexes.md).

# Partial Indexes

Create an index on a subset of the entire table. This potentially reduces its size and the amount of overhead to maintain it.

One common use case is to partition indexes by date ranges

-> Create a separate index per month, year.
