[ORALCE]SQL 优化案例之 TABLE ACCESS BY USER ROWID【代码】

ROWID访问数据行最快，在实际应用中可以采用 生成测试数据：drop table tx1 purge; create table tx1 as select * from dba_objects; update tx1 set object_id=rownum; commit;set autotrace traceonly set linesize 160 exec dbms_stats.gather_table_stats(SYS,TX1,estimate_percent =>100,method_opt=>for all indexed columns,cascade=>true); SQL> select rowid from TX1 where object_id=188;ROWID ------------------ AAAS...