How can we determine if the Oracle index is working eff…
To check if Oracle indexes are effective, you can use the following method:
- By using the EXPLAIN PLAN statement, you can add “EXPLAIN PLAN FOR” before the query statement and then use “SELECT * FROM TABLE(DBMS_XPLAN.DISPLAY)” to view the execution plan. The execution plan will show the indexes and access paths used by the query statement. If an index is used, it means that the index is effective.
- By utilizing SQL Trace, you can enable SQL tracing by using the SET_TRACE_ENABLE procedure in the DBMS_MONITOR package, then execute the query statement and disable tracing. The tracing file will contain execution information of the query statement, including the indexes used. By analyzing the tracing file, you can determine if the indexes are effective.
- By utilizing Oracle’s automatic tracing feature, you can set the database parameter “_optimizer_trace” to enable this function. Subsequently running a query will generate a trace file in Oracle, containing information on the query’s execution, including the indexes used.
- Utilizing SQL Developer or other database tools allows for the examination of query execution plans and index usage through their performance analysis features. These tools typically offer a visual interface for easily determining if an index is being utilized.
Regardless of the method used, it is important to ensure that the database statistics are up-to-date and that the binding variables in the query statements are different each time they are executed in order to accurately evaluate the effectiveness of the indexes.
