What is 'Garbage Collection' in a database?

What is 'Garbage Collection' in a database?

Approach: Explain reclaiming space from deleted rows.

The process of identifying and reclaiming storage space that was occupied by data versions no longer needed by any active transaction (e.g., after an UPDATE or DELETE).

Follow-up: What is the VACUUM command in Postgres?

Key concepts: vacuum, mvcc, bloat.