SQL Tutorials & Guides

Zero-Downtime Postgres Migrations: Expand-Contract in Practice

A single ALTER TABLE took a lock and stalled every write for 40 seconds during peak traffic. Expand-contract is how we stopped shipping outages.

Hunting Slow Queries with pg_stat_statements

The dashboard said the database was fine. It wasn't. Here's how pg_stat_statements found the query eating 40% of our Postgres CPU.

Time-Series Postgres: Declarative Partitioning in Practice

A 900GB events table where every query scanned four years to read one day. Range partitioning by month cut our dashboard queries from 8s to under 200ms.

Postgres Index Bloat: Detecting and Fixing It Before It Hurts

A 40GB index on a 6GB table was the first sign. Queries were fine until they weren't. Here's how we found the bloat and cleared it with zero downtime.

Postgres Logical Replication for Zero-Downtime Major Upgrades

pg_upgrade is fast but takes downtime; logical replication lets you cut over while the old DB still serves traffic. The runbook, the gotchas, and the post-cutover checklist.

pg_stat_statements — Postgres Query Analysis Without Guessing

The single most useful Postgres extension you might not be using. The queries it surfaces, the indexes it implies, and the operational discipline of reading it weekly.

Postgres Query Plans — Reading Them and the Indexes We Wish We'd Added Sooner

EXPLAIN ANALYZE output is dense and intimidating. Once you can read it, most slow-query investigations finish in minutes. The patterns we keep seeing.

KU

Kiril Urbonas·23

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