PostgreSQL

PostgreSQL from an application engineer's perspective — indexing, query planning, schema design, transactions and diagnosing slow queries.

Aug 24, 2026PostgreSQL8 min

PostgreSQL Indexes Explained: How They Actually Improve Query Performance

What a B-tree index really does, how to read EXPLAIN ANALYZE, why column order in composite indexes matters, and when adding an index makes a query slower instead of faster.

#Databases
#Indexing
#Performance
#PostgreSQL
#SQL