数据库 性能 检查语句

--ORACLE中的所有函数
SELECT * FROM V$SQLFN_METADATA;

--全表扫描
SELECT *
  FROM V$SQL_PLAN
 WHERE OPERATION = 'TABLE ACCESS'
   AND OPTIONS = 'FULL';

--索引全扫
SELECT *
  FROM V$SQL_PLAN
 WHERE OPERATION = 'INDEX'
   AND OPTIONS = 'FULL SCAN';

--索引全扫
SELECT *
  FROM V$SQL_PLAN
 WHERE OPERATION = 'INDEX'
   AND OPTIONS = 'SKIP SCAN';

--查询条件与列类型不一致
SELECT *
  FROM V$SQL_PLAN
 WHERE FILTER_PREDICATES IS NOT NULL
   AND INSTR(FILTER_PREDICATES, 'INTERNAL_FUNCTION') > 0;

--笛卡尔积
SELECT * FROM V$SQL_PLAN WHERE OPERATION = 'CARTESIAN';