Pelin
When should I switch to a covering index with INCLUDE to get an index-only scan?
Add `INCLUDE` only when the query is hot and `EXPLAIN (ANALYZE, BUFFERS)` shows heap access dominating, then tighten autovacuum until `Heap Fetches: 0`.
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#Database
Database choice, schema, query and operational decisions that outlive the engine. Questions under this tag, answered directly.
19 answered questions carry this tag.
Yiğit
Should I use a partial index on a queue table where I only ever scan 'pending' rows?
Build the partial index on `WHERE status='pending'`, include the `ORDER BY` column, pair it with `FOR UPDATE SKIP LOCKED`, and pass 'pending' literally.
Çağrı
Why is keeping the key in .env risky when encrypting sensitive financial data — what do KMS/Vault give you?
Take the key out of .env, keep it in KMS or Vault and use envelope encryption; for national IDs and card data, prefer tokenization wherever you can.
Yusuf
How do I rewind to seconds before a disaster with WAL archiving and PITR?
Take a periodic base backup, archive WAL to S3 continuously, replay to a recovery_target_time seconds before the bad statement, and rehearse the restore.
Melih
How do I run database migrations safely in CI/CD?
Add the column nullable, move the backfill to a separate throttled step, run migrations in their own stage, and drop the old column in a later release.
Uğur
Time-series data: TimescaleDB or InfluxDB?
100M rows a day breaks a plain table, so chunk it by time with hypertables, materialize the averages as continuous aggregates, and compress the old chunks.
Taylan
How do I coordinate a zero-loss schema migration with dual-writing on a live table?
Instead of a blocking `ALTER TABLE` on 20M rows run expand/contract: add nullable columns, dual-write, backfill in throttled batches, then drop the old.
Sarp
Why should I use a Sorted Set for a live leaderboard in Redis?
Use a Sorted Set instead of plain string keys sorted in the app, since `ZADD` updates in O(log N) and `ZREVRANGE 0 99` returns the top 100 already ordered.
Rüzgar
When should I apply CQRS, and how do I sync the read and write models?
Move reporting to a read replica and adopt CQRS only when query shapes outgrow one schema, feeding the read model from outbox events, not dual-writes.
Halil
Should I choose NoSQL or PostgreSQL for flexible product attributes?
Keep products, prices and orders in PostgreSQL and put the variable attributes in one GIN-indexed `JSONB` column; reporting alone rules out splitting.