
上QQ阅读APP看书,第一时间看更新
Getting ready
You can check the explain plan in SQLA or using Studio Express. The explain plan can also be generated in BTEQ but it would not be easy to read it. Explain is produced in plain simple English text.
It is a good practice to run an EXPLAIN of the query before submitting it for execution. In the explain plan we need to check the join type, execution time, and confidence level of the execution steps.