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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Tag
#Performance
Latency, throughput and resource use: performance work that starts with a measurement. Questions under this tag, answered directly.
16 answered questions carry this tag.
Naz
Should I use chunkById instead of chunk when the same job also updates the rows it iterates?
Use `chunkById()` when there is real per-row work and never touch the cursor column; if you only update a column, switch to one set-based `UPDATE`.
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.
Zeynep
Why does a query use an Index Scan in staging but a Seq Scan in production, and how do I diagnose it with EXPLAIN?
Run EXPLAIN (ANALYZE, BUFFERS) in production, then ANALYZE the table and check n_dead_tup; tune autovacuum per-table for sessions and add a partial index.
Ayşe
Should I enable Model::preventLazyLoading only locally or in production too?
Run it fully strict and throwing in local and CI; in production keep it on but wire handleLazyLoadingViolationUsing to log without failing the request.
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.
Aslı
How do I set up CDN asset versioning: hashing and a cache strategy on deploy?
Drop query-string busting: cache content-hashed filenames as `immutable`, keep the HTML short-lived, and upload the assets before you cut over.
Efe
How do I make search-as-you-type fast with edge n-grams in Elasticsearch?
Drop wildcard for autocomplete; build the prefixes at index time with edge_ngram and keep a standard search analyzer so a keystroke is a plain term lookup.
Barış
How do I stream 2-5 GB file downloads without blowing up PHP's memory?
Serve 2-5 GB files outside PHP via a presigned URL or X-Accel-Redirect; if it must go through PHP, chunk it with readStream and turn off buffering.
Kerem
How do HTTP/2 and HTTP/3 (QUIC) improve API performance?
Turn on HTTP/2 today, since multiplexing collapses 4-5 requests per screen onto one connection; add HTTP/3 for a mobile audience and drop domain sharding.