PostgreSQL taste

Reviews SQL queries and optional EXPLAIN output for common performance problems such as SELECT *, functions or casts on indexed columns, leading-wildcard LIKE, N+1 query loops, OR across columns vs UNION ALL, AND/OR precedence slips, NOT IN subqueries, deep OFFSET paging, seq scans and disk sorts. Explains each problem and gives a rewritten query. Includes a stdlib Python checker with --self-test. 来源：https://prompts.chat/prompts/cmvni9hqj000gi308xwj9rj0t

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

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 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