Hi,

I need to write a query to find whether a particular record exists or not in a table. Basically I want the query to return a single value if the record is found.

Below are the possible solutions

SELECT 1
FROM MSG_STATUS
WHERE MSST_MSG_CTRL = 'H50344'
FETCH FIRST 1 ROW ONLY

SELECT distinct 1
FROM MSG_STATUS
WHERE MSST_MSG_CTRL = 'H50344'

SELECT COUNT(*)
FROM MSG_STATUS
WHERE MSST_MSG_CTRL = 'H50344'

SELECT 1
FROM SYSIBM.SYSDUMMY1 A
WHERE EXISTS (
SELECT 1 FROM
FROM MSG_STATUS
WHERE MSST_MSG_CTRL= 'H50344'
AND A.IBMREQD = A.IBMREQD
)

Is there any other way I can know whether the record is there or not .. performance is really a issue has the table contains records in lakhs or more

Pls let me know…

Regards

dilip

Hi,

1. Try using explain to find out the costs.
2. Consider of making index on column MSST_MSG_CTRL.

Hope this helps,
Grofaty