Understanding the results of Execute Explain Plan in Oracle SQL Developer

Question

I\'m trying to optimize a query but don\'t quite understand some of the information returned from Explain Plan. Can anyone tell me the significance of the O

Answer 1

Here is a reference for using EXPLAIN PLAN with Oracle: http://download.oracle.com/docs/cd/B19306_01/server.102/b14211/ex_plan.htm), with specific information about the columns found here: http://download.oracle.com/docs/cd/B19306_01/server.102/b14211/ex_plan.htm#i18300

Your mention of 'FULL' indicates to me that the query is doing a full-table scan to find your data. This is okay, in certain situations, otherwise an indicator of poor indexing / query writing.

Generally, with explain plans, you want to ensure your query is utilizing keys, thus Oracle can find the data you're looking for with accessing the least number of rows possible. Ultimately, you can sometime only get so far with the architecture of your tables. If the costs remain too high, you may have to think about adjusting the layout of your schema to be more performance based.