I need to execute someth开发者_如何学运维ing like:
select
[very big SQL]
where phone_number in(:SQL2)
Is it possible to use bind variable for SQL2?
I want to save the execution plan of the major SQL.Thanks.
Create a temporary table and save SQL2
's results there prior to executing SQL1
:
CREATE GLOBAL TEMPORARY TABLE mytemptable (id INT NOT NULL)
CREATE OUTLINE ol_sql1
ON
SELECT *
FROM sql1
WHERE id IN
(
SELECT id
FROM mytemptable
)
INSERT
INTO mytemptable
SELECT *
FROM sql2
SELECT *
FROM sql1
WHERE id IN
(
SELECT id
FROM mytemptable
)
If this query gets executed a lot of times, I wouldn't use a temporary table for it.
There is a 'trick' to bind an inlist, which Tom Kyte describes on his blog:
http://tkyte.blogspot.com/2006/06/varying-in-lists.html
I would bet on that being much more efficient. It should be easy to prove with a SQL Trace.
Further to Quassanoi's point. It sounds like you may not be familiar with temporary tables. This is a good introduction.
You only create the table once. Then within a given session you first:
- populate the temporary table
- execute your query pulling from the temporary table
- rollback.
There's no risk of conflicting/overlapping with another session's data.
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