oracle_执行计划_谓词信息和数据获取

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SQL> create index zhou_t_idx on zhou_t(x,y);索引已创建。SQL> select /*+rule*/ * from zhou_t where x=5;执行计划----------------------Plan hash value: 42197324---------------------------------------| Id | Operation | Name |---------------------------------------| 0 | SELECT STATEMENT | ||* 1 | INDEX RANGE SCAN| ZHOU_T_IDX |---------------------------------------Predicate Information (identified by operation id):--------------------------------------------------- 1 - access("X"=5)Note------ rule based optimizer used (consider using cbo)?

从上面可以看到，谓词条件影响到数据访问的路径------选择了索引，所以用access