Create Volatile Table in Teradata

About VOLATILE:

You are working in a Teradata database application. You have to CREATE a table and insert some records for performance analysis. You have to DROP the table once you have done with your job. If this is the case, will you think a smart way for this?

Yeah. Teradata gives VOLATILE option with CREATE TABLE syntax.

What special ?

If you create table with VOLATILE option, the life of the table will be only for the current session.
It will be automatically dropped by Teradata manager once session expires. (Both definition and content)

Syntax:
/* Volatile Table Syntax - Teradata */
CREATE VOLATILE TABLE table_1
(
column1 datatype,
column2 datatype,
.
.
columnN datatype
);



CREATE VOLATILE TABLE employee
(
ID INT,
Name VARCHAR(20)
);


Interesting about VOLATILE:

Now, you are creating a VOLATILE table and inserting some records successfully into it.
SELECT * from the volatile table. Shocked ? ...
Yes. You cannot see the records because Teradata becomes strict to VOLATILE tables by incorporating ON COMMIT DELETE ROWS by default to add more meaning to VOLATILE.

so, if you want to see the records you have to explicitly write ON COMMIT PRESERVE ROWS immediately after CREATE TABLE syntax.

CREATE VOLATILE TABLE table_1
(
column1 datatype,
column2 datatype,
.
.
columnN datatype
) ON COMMIT PRESERVE ROWS;



More about VOLATILE:

1. You can have 1000 volatile tables in an active session.
2. CHECK and REFERENTIAL constraints are not allowed.
3. DEFAULT clause not allowed.


Here VOLATILE says, DO and GO.. i will take care...

..