# db-skills — Database Management Skill Collection

Author: Simon-Pierre Boucher Contact: contact@spboucher.ai

Ten ultra-sharp database-management skills following the method in ../RESEARCH-SYNTHESIS.md, grounded in current practice (3NF-first design, measure-before-tuning with EXPLAIN ANALYZE / pg_stat_statements, index every foreign key, expand→migrate→contract zero-downtime migrations, 3-2-1 backups with restore drills). PostgreSQL is the default dialect; deviations for MySQL/SQLite are noted where they matter. All pass python3 ../tools/validate_skills.py.

# The collection and its boundaries

Skill	Handles	Explicitly does NOT handle
`writing-sql-queries`	correct, readable, parameterized SQL; CTEs; window functions; NULL traps	schema design → `designing-database-schemas`; tuning → `optimizing-sql-performance`
`designing-database-schemas`	domain modeling, 3NF, keys, types, constraints, naming	query writing; migration mechanics; NoSQL → `modeling-nosql-data`
`optimizing-sql-performance`	EXPLAIN ANALYZE, indexes, plans, N+1, keyset pagination	incidents → `troubleshooting-databases`; fresh schema design
`managing-database-migrations`	versioned, immutable, reversible migrations; zero-downtime patterns	target-schema design; one-off data fixes
`backing-up-databases`	scheduled backups, logical vs physical, PITR, 3-2-1, restore drills	HA/replication setup; migrations
`securing-databases`	least-privilege roles, injection defense, secrets, TLS, RLS, auditing	app-level auth (sessions/JWT); general firewalls
`administering-postgresql`	roles, config knobs, autovacuum, monitoring, upgrades	app query tuning; backup strategy
`managing-sqlite`	WAL, pragmas, transactions, safe backup, type affinity	server databases; generic SQL writing
`modeling-nosql-data`	access-pattern-first modeling, embed vs reference, key design, TTL	relational schemas; JSON columns in SQL databases
`troubleshooting-databases`	incident triage runbook: connections → locks → slow queries → disk → replication	proactive tuning; server configuration

# Shared conventions

Description = WHAT + "Use when …" (literal phrases) + "Do not use for …"
Measure before changing anything; capture evidence before restarting anything
One default per decision (tool, key type, journal mode) with an escape hatch
Every workflow ends with a validation step (test restore, rollback rehearsal, EXPLAIN before/after)
SKILL.md <150 lines; depth in references/patterns.md (with TOC)