标签：rman statistic Plan sql creat this update ESS test
Should we create any index suggested by the SQL Execution Plan?
Automatically? No. you have to look at the Impact first.
Also, you have to test it and make sure it will enhance the performance of your query.
Should we concentrate on the arrow thickness in all cases?
You need to make sure that the arrow is thick at the beginning and getting thinner after that. Such as returning 2 rows after scanning thousands of records.
Can the Estimated SQL Execution Plan result be trusted?
This depends on the statistics. If it is updated the results should be the same. You need the Estimated SQL Execution Plan in case the query will take long time to execute and you need to troubleshoot it.
How to Analyze SQL Execution Plan Graphical Components
标签：rman statistic Plan sql creat this update ESS test
原文地址：https://www.cnblogs.com/chucklu/p/14821882.html
