Postgres Covering Indexes and the Visibility Map
Optimize PostgreSQL query performance using covering indexes and visibility maps to enable efficient index-only scans
Covering indexes in PostgreSQL allow queries to be satisfied directly from the index, reducing I/O by leveraging the visibility map. Index-only scans become possible when all required columns are included in the index, and the visibility map tracks which rows are visible. Designing indexes to maximize this effect is a best practice for optimizing read-heavy workloads.
