Difference Between Execution Plan and Explain Plan in Oracle

EXPLAIN PLAN output shows how the database would have run the SQL statement when the statement was explained. Just as in the driving example above Oracle may use a different route than the one it predicted.

Explain Plan

The main difference between the AUTOTRACE and EXPLAIN PLAN commands in Oracle is that AUTOTRACE actually executes the query in the way TRACE does and automatically queries the plan table whereas EXPLAIN PLAN does neither.

. The SQL is identical so I would expect that the SQL explain plan would not be different. A statements execution plan is the sequence of operations Oracle performs to run the statement. An execution plan describes the steps it actually took.

My favorite column other_xml. Select from emp where empno736. An explain plan predicts how Oracle will process your query.

But I have also read that Execute plan is the plan which Oracle Optimizer intends to use for the query and actual execute plan might be different. On production the query execution plan it picks for most queries is different from development and the cost is somtimes 1000x higher. As per my knowledge explain plan gives you the execute plan of the query.

So i started exploring plan_table and voilathere it was. So to diagnose your queries you need to know what Oracle did. A statements execution plan is the sequence of operations Oracle performs to run the statement.

The row source tree is the core of the execution plan. What is the difference between execution plan. What is the difference between explain plan and execution plan in Oracle.

If this is the case then how do I get the ACTUAL EXECUTE PLAN which the optimizer used for executing the query after execution. The EXPLAIN PLAN statement displays execution plans chosen by the Oracle optimizer for SELECT UPDATE INSERT and DELETE statements. An explain plan predicts how Oracle will.

The explain plan is what the optimizer thinks will happen when you run the execution plan is actually happened when you ran the query. The EXPLAIN PLAN statement displays execution plans that the optimizer chooses for SELECT UPDATE INSERT and DELETE statements. All tablesindexes are the same but the dev database has about 110th the rows for each table.

Click to see full answer. A statements execution plan is the sequence of operations Oracle performs to run the statement. It shows the following information.

A statements execution plan is the sequence of operations Oracle performs to run the statement. By now you must have realized that oracle stores all the hints and some other stuff like plan_hash2-This i will explain in some other post in this column. The row source tree is the core of the execution plan.

The AUTOTRACE command generates similar information as shown in the next listing. In other words why not sync my explain plan and execution plan. The explain plan is what the optimizer thinks will happen when you run the execution plan is actually happened when you ran the query Not sure my understanding is correct or I misunderstood the above article.

Could you please let me know the differenece between execution plan and explain plan Could you please let me know whether I have to analyze and work on whether Execution plan or Explain plan which i have generated as follows. As Tom Kyte discusses there are several reasons this could happen. The row source tree is the core of the execution plan.

1 set autotrace traceonly. The EXPLAIN PLAN statement displays execution plans chosen by the Oracle optimizer for SELECT UPDATE INSERT and DELETE statements. How can I tell why a SQL execution plan is different on different servers.

The cost-based optimizer CBO looks at many factors when deciding the best execution plan and it is not uncommon to find the same SQL with a very different execution plan. The EXPLAIN PLAN statement displays execution plans chosen by the Oracle optimizer for SELECT UPDATE INSERT and DELETE statements. They are both Oracle 9i but almost every single query has a completely different execution plan depending on the database.

83 rows The EXPLAIN PLAN statement displays execution plans chosen by the Oracle optimizer for SELECT UPDATE INSERT and DELETE statements. Because of differences in the execution environment and explain plan environment the explained plan can differ from. 2 explain plan for select from emp where empno736.

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