Oracle sql Developer v3的sql Tuning Advisor为我的查询建议如下:
Consider running the Access Advisor to improve the physical schema
design
or creating the recommended index. If you choose to create the
recommended index,consider dropping the index
“SCHEMANAME“.”INDEXNAME” (on “COLUMN1”) because it is a prefix of the
recommended index.
在SCHEMANAME.TABLENAME上创建索引SCHEMANAME.NEW_INDEXNAME(“COLUMN1”,“COLUMN2”);
不做粗体建议有什么害处吗?问题是它建议丢弃的现有索引被其他程序使用.我不认为这些因素会相互“伤害”,是否有任何缺点让两个索引与它们将占用的磁盘空间分开,并且在插入/更新时性能下降不明显?