Database Administrator
PostgreSQL questions
49 questions on PostgreSQL for database administrators, easiest first.
Easy 10
Medium 22
- Reading an EXPLAIN ANALYZE planmedium
- Why PostgreSQL needs VACUUMmedium
- What PITR needsmedium
- Why use a connection poolermedium
- Covering indexmedium
- Which query to tune firstmedium
- UNIQUE column with NULLsmedium
- Adding an index on a live tablemedium
- Sort Method: external mergemedium
- Bad plan right after a bulk loadmedium
- Sizing shared_buffersmedium
- Session state behind pgBouncermedium
- Workers fighting over jobsmedium
- Reports cancelled on the replicamedium
- Is pg_dump consistent?medium
- Disk not freed after a big deletemedium
- Bloat from an idle sessionmedium
- A migration froze the whole appmedium
- Indexing only pending rowsmedium
- Searching inside textmedium
- Fast JSONB filtersmedium
- Counting a huge table quicklymedium
Hard 17
- Transaction ID wraparoundhard
- Index ignored because of a functionhard
- Disk filling with WALhard
- Prepared statement slows down laterhard
- Estimates wrong for city and zip codehard
- Logical replication stopped after a migrationhard
- pg_upgrade --link and rollbackhard
- pg_wal growing without limithard
- Unique email on a partitioned tablehard
- Deleting old data every monthhard
- Primary demoted when etcd is unreachablehard
- WAL volume spikes after checkpointshard
- Row-level security not appliedhard
- Risky SECURITY DEFINER functionhard
- Indexes bloat on a counter tablehard
- OOM killer after raising work_memhard
- Locks held by nobodyhard