what is explain plan?, given an example...
Answers were Sorted based on User's Feedback
Answer / shivainduja
An explain plan is a representation of the access path that
is taken when a query is executed within Oracle.
SQL> explain plan for select * from emp2;
Explained.
SQL> select * from table (DBMS_XPLAN.display);
PLAN_TABLE_OUTPUT
-------------------------------------
Plan hash value: 2941272003
--------------------------------------------------------------------------
| Id | Operation | Name | Rows | Bytes | Cost
(%CPU)| Time |
--------------------------------------------------------------------------
| 0 | SELECT STATEMENT | | 15 | 570 | 3
(0)| 00:00:01 |
| 1 | TABLE ACCESS FULL| EMP2 | 15 | 570 | 3
(0)| 00:00:01 |
--------------------------------------------------------------------------
8 rows selected.
Is This Answer Correct ? | 4 Yes | 1 No |
Answer / rajesh venati
this will also work.
An Explain Plan is a tool that you can use to have Oracle
explain to you how it plans on executing your query.
ex:-
SQL> set autotrace on explain
SQL> select * from emp;
Execution Plan
----------------------------------------------------------
Plan hash value: 3956160932
--------------------------------------------------------------------------
| Id | Operation | Name | Rows | Bytes | Cost
(%CPU)| Time |
--------------------------------------------------------------------------
| 0 | SELECT STATEMENT | | 14 | 518 | 3
(0)| 00:00:01 |
| 1 | TABLE ACCESS FULL| EMP | 14 | 518 | 3
(0)| 00:00:01 |
--------------------------------------------------------------------------
Is This Answer Correct ? | 1 Yes | 0 No |
Explain Plan determines the execution plan of SQL statement.
Is This Answer Correct ? | 0 Yes | 0 No |
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