Improving the performance

Question

hi,
i am using one global temporary table for a process
if instead of that if i use a regular table which contains some 200 million records for some 5 different clients.
each client may have some 40 million record.
which one will give better performance global temporary table or regular table (in where condition i will put client=xxx
(i am just going to fetch the record from the table for processing)
please help

Answer 1

Hi,
Read this....
Using Temporary Tables To Improve Performance
You can use temporary tables to improve performance when you run complex queries. Running multiple such queries is relatively slow because the tables are accessed multiple times for each returned row. It is faster to cache the values from a complex query in a temporary table, then run the queries against the temporary table.
For example, even with a view like this defined to simplify further queries, the queries against the view may be slow because the contents of the view are recalculated each time:
CREATE OR REPLACE VIEW Profile_values_view AS
SELECT d.Profile_option_name, d.Profile_option_id, Profile_option_value,
u.User_name, Level_id, Level_code
FROM Profile_definitions d, Profile_values v, Profile_users u
WHERE d.Profile_option_id = v.Profile_option_id
AND ((Level_code = 'USER' AND Level_id = U.User_id) OR
(Level_code = 'DEPARTMENT' AND Level_id = U.Department_id) OR
(Level_code = 'SITE'));
A temporary table allows us to run the computation once, and cache the result in later SQL queries and joins:
CREATE GLOBAL TEMPORARY TABLE Profile_values_temp
Profile_option_name VARCHAR(60) NOT NULL,
Profile_option_id NUMBER(4) NOT NULL,
Profile_option_value VARCHAR2(20) NOT NULL,
Level_code VARCHAR2(10) ,
Level_id NUMBER(4) ,
CONSTRAINT Profile_values_temp_pk
PRIMARY KEY (Profile_option_id)
) ON COMMIT PRESERVE ROWS ORGANIZATION INDEX;
INSERT INTO Profile_values_temp
(Profile_option_name, Profile_option_id, Profile_option_value,
Level_code, Level_id)
SELECT Profile_option_name, Profile_option_id, Profile_option_value,
Level_code, Level_id
FROM Profile_values_view;
COMMIT;
Now the temporary table can be used to speed up queries, and the results cached in the temporary table are freed automatically by the database when the session ends.
Enjoy Performance ...
Rgds,
Rup