Sql PERFORMANCE in Oracle

[crisck]

I wonder if anyone knows any software that returns the time spent to accomplish the given query.
For example, I have the query and the query B, I would like to know which of the two is faster.
For this I need to know the time taken by the query and the query b. How do that?
Grateful

[victorhugomuniz]

sql navigator says the hour which begins and ends the query just rotate out one at a time and do the math the plsql developer reports the time spent executing the query dai and so run one at a time and I'm pretty sure the sql developer also makes this tip: take the time for samplingturn at least 5 times the query and make the average to have a runtime \"more real\"

[dr_gori]

Tell the time or always shows a real information. Example: * you spin a query that takes 1 minute to finish. Later, wheel again and the same query takes 1 second. That's because all rows are in the buffers and there is no need to consult everything again on the disks.

So the ideal is to query the execution plan and separate things. (I know there's a way to clear the buffers, it is ideal to clean before doing these tests)

[crisck]

so. .. My problem just é know how much a sql statement.
for example: a dependent student FIRST) Select * from employee f, d where f.id = d.id dependent _ SECOND employee) Select * from employee f dependent join d on (f.id = d.id _ student) so I have two queries for example, which one is faster? and if you replace the order of entities in the clause from the FIRST, there would be changes in performance?
If invertessemos the join in the second, improving on something?
These doubts are getting sleep ....

[Trevisolli]

Brother, To know the cost of the query, there are two ways (that I know): 1) through the generation of Trace/query Tkprof (check with a DBA for realization of process/support);
2) through Visual Tools, such as the Explain Plan SQL Navigator;