Database Skills
Explore 7 curated database skills for building with AI coding agents — what each one does, when to use it, and how to add it to your workflow.
Connection Pool Tuner
Size and tune a database connection pool from the real constraint — the database's shared max_connections and its core count — so total connections (per-instance pool × instance count) stay safely under the cap and a too-large pool stops adding latency. Use when the app throws 'too many connections' or pool-acquire timeouts, when the DB is saturated by connection count, or when deploying to serverless.
Deadlock Diagnoser
Diagnose a database deadlock from the engine's own deadlock report, reconstruct the lock cycle (A holds 1 wants 2, B holds 2 wants 1), name the root cause — almost always two code paths locking the same rows in different orders — and fix it with consistent lock ordering, shorter transactions, and a retry-the-victim safeguard. Use when the DB logs deadlock errors, when transactions intermittently fail under load, or when queries mysteriously block each other.
Embedding Index Tuner
Tune a vector index — HNSW graph parameters and quantization — to hit a recall target at the lowest latency and memory, by sweeping settings against a fixed query set instead of trusting defaults. Use when vector search is slow or memory-hungry, when recall dropped after enabling quantization, or when standing up an index and you need defensible parameters.
Migration Writer
Write a safe, reversible, zero-downtime database migration using expand-contract — add the new shape, backfill in batches, switch reads/writes, then drop the old — so every deploy stays compatible with the running app version. Use when adding or changing schema on a live system, renaming/dropping a column, adding NOT NULL or a foreign key on a large table, or when a migration risks locks, table rewrites, or an unrevertable step.
Postgres Index Strategist
Recommend the right Postgres index for a query or workload — choosing B-Tree vs. GIN vs. BRIN vs. partial/covering/expression, checking for redundant or unused indexes, and verifying the choice against the query plan. Use when a query needs an index, when deciding an index type for jsonb/array/full-text/time-series data, or when auditing an over-indexed table.
Query Plan Analyzer
Read a slow query's execution plan and turn it into a concrete fix — the exact index to add, the rewrite, or the ANALYZE to run — by getting the REAL plan with EXPLAIN ANALYZE (actual rows + timing, not estimates), finding the offending node, and confirming the fix removes it. Use when one specific query is slow and you need to know WHY, not just that it is.
Safe Data Backfill Planner
Plan and implement a resumable production data backfill with bounded batches, checkpoints, rate limits, correctness verification, observability, and a pause or rollback path. Use when populating a new column, repairing historical rows, re-keying records, migrating derived data, or updating millions of records without overwhelming the database or replicas.