TLDR Dev · ARTICLES & TUTORIALS

THINGS YOU DIDN'T KNOW ABOUT INDEXES

jon.chrt.dev12 min read

Summary from the TLDR Dev newsletter

Database indexes speed update retrieval by providing a sorted structure that bypasses slow full table scans. However, they come with trade-offs, making writes slower, consuming storage, and requiring careful implementation to avoid pitfalls like incorrect composite index order or applying functions to indexed columns. Tools like `EXPLAIN` help diagnose index usage, while specialized types such as functional indexes (for expressions) and partial indexes (for data subsets) address specific query patterns.