How to measure performance of query in oracle

Question

I\'m new to Oracle db. I have 2 queries which return the same result set. I want to measure the performance of each of them and choose the better one. How do I do that using Ora

Answer 1

There is button above the SQL editor called "Explain Plan". This tool will tell you what each route costs, and how the statement will use indexes and partitions. Note, you may get an error, your DBA will need to turn on a feature for your user account, I believe it is "trace", but could be wrong on that point. Reading the execute statement output can be challenging at first, but it is a good tool to helping write good SQL.