Reviews PostgreSQL and MySQL tables (schema.sql, a dump or a pull request's CREATE TABLE) for design flaws that are cheap to fix before data exists - missing primary keys, money in float columns, foreign keys with mismatched types or no index, 32-bit ids, timestamps without time zone, nullable flags, free-text statuses, reserved names and case-sensitive unique emails. Returns corrected DDL. Includes a stdlib Python linter with --self-test. 来源：https://prompts.chat/prompts/cmvt899cc0015lb076u345t0n
Reviews a schema and slow SQL queries, proposes composite indexes in the right column order (equality, sort, range) with covering columns and tradeoffs, flags non-sargable filters like functions on columns and leading-wildcard LIKE, and warns about duplicate, redundant, and low-selectivity indexes. Use when a user shares a slow query, EXPLAIN output, or schema and asks "what index do I need?" or "too many indexes?". Includes a tested stdlib Python helper. 来源：https://prompts.chat/prompts/cmv6dyatr000bl80667elnhdv
Sizes database connection pools for Postgres/MySQL apps from a short JSON of services, pods, workers, threads and pool settings - worst-case connections at autoscale max and during deploy surges vs max_connections, busy connections from rps x hold time, per-process wait odds (Erlang C), CPU and memory limits, PgBouncer client and server limits. Recommends pool sizes or proxy settings. Includes an offline stdlib Python calculator with --self-test. 来源：https://prompts.chat/prompts/cmvxi8kpe0008l508b4ttzkaq
Reviews PostgreSQL and MySQL schema migrations (raw SQL or ORM-generated) for table locks, rewrites, data loss, and breaking changes, then proposes safe zero-downtime rewrites with a clear verdict. 来源：https://prompts.chat/prompts/cmureuo3w0001lb06x7qn6vyo
