Glossary

Postgres · Reference cheat sheet

📋 Overview

Alphabetical glossary of PostgreSQL operations and administration terms.

Term	Definition
Autovacuum	Background process that vacuums and analyzes tables.
Bloat	Excess space from dead tuples / index waste.
Checkpoint	Flush dirty buffers and advance WAL recovery point.
Concurrent index	Index build that avoids long write locks.
Extension	Packaged set of DB objects installed per database.
Hot standby	Replica open for read-only queries.
MVCC	Multi-version concurrency control for readers/writers.
PITR	Point-in-time recovery using base backup + WAL.
Pooler	Middleware multiplexing client connections.
Role	Auth identity that can own objects and hold privileges.
TOAST	Out-of-line storage for large field values.
Vacuum	Cleanup of dead row versions for reuse.
WAL	Write-ahead log guaranteeing durability and replication.
Wraparound	Transaction ID exhaustion risk mitigated by freezing.

Activity snapshot:

SELECT pid, usename, state, query_start, left(query, 80)
FROM pg_stat_activity
WHERE state <> 'idle';

Extension list:

\dx

Glossaries compress nuance — always confirm behavior for your major version (14/15/16/17).
Managed Postgres may rename or restrict low-level ops (superuser, FS access).