Add a new databases category with three subcategories: postgres,
redis, and sql-tuning. Each subcategory holds 10 self-contained tests
with deterministic evaluators.
Postgres tests cover EXPLAIN interpretation, index choice, N+1
detection, isolation anomalies, deadlocks, replica failover, bloat
diagnosis, pool sizing, partial indexes, and LISTEN/NOTIFY.
Redis tests cover structure choice, TTL eviction, INCR atomicity,
MULTI versus pipelining, and SCAN versus KEYS. They also cover pub/sub
delivery, Lua atomicity, memory estimation, cache stampede mitigation,
and keyspace anti-patterns. The SCAN versus KEYS test uses a
negation-aware evaluator, so a response that warns against KEYS does
not lose credit for mentioning it.
SQL-tuning tests trace query results against an inline orders table:
aggregates, joins, NULL handling, GROUP BY plus HAVING, and window
functions. The unit tests recompute every numeric or JSON answer
independently, with a hand-written loop separate from the production
query-logic helper.
registerDatabasesTests registers the category. A wiring test verifies
it directly, and the code does not touch catalog.go, so the
orchestrator can wire the category in separately during integration.
