Planned schema changes:
CREATE EXTENSION IF NOT EXISTS "pg_trgm";
-- Modify function generate_case_id: body, language
CREATE OR REPLACE FUNCTION "generate_case_id"() RETURNS varchar(20) AS $$
DECLARE
    v_today VARCHAR(8);
    v_seq   INTEGER;
BEGIN
    v_today := TO_CHAR(CURRENT_DATE, 'YYYYMMDD');
    -- 事务级排他锁（双参数，无 int32 哈希碰撞风险）：不同天并行，同天串行
    PERFORM pg_advisory_xact_lock(hashtext('generate_case_id'), v_today::integer);
    SELECT COALESCE(MAX(CAST(SUBSTRING(case_id FROM 10 FOR 5) AS INTEGER)), 0) + 1
        INTO v_seq FROM "case"
        WHERE case_id LIKE 'Q' || v_today || '%';
    RETURN 'Q' || v_today || LPAD(v_seq::TEXT, 5, '0');
END;
$$
LANGUAGE plpgsql SECURITY INVOKER VOLATILE;
CREATE TRIGGER "update_user_updated_at" BEFORE UPDATE ON "user" FOR EACH ROW EXECUTE FUNCTION "update_updated_at_column"();
CREATE INDEX IF NOT EXISTS "idx_kb_category_embedding" ON "kb_category" USING ivfflat ("embedding" vector_cosine_ops) WITH (lists='100');
Auto-approval enabled; applying schema changes.
Schema apply completed successfully.