How to query range of data in DB2 with highest performance?
- by Fuangwith S.
Usually, I need to retrieve data from a table in some range; for example, a separate page for each search result. In MySQL I use LIMIT keyword but in DB2 I don't know. Now I use this query for retrieve range of data.
SELECT *
FROM(
SELECT
SMALLINT(RANK() OVER(ORDER BY NAME DESC)) AS RUNNING_NO
, DATA_KEY_VALUE
, SHOW_PRIORITY
FROM
EMPLOYEE
WHERE
NAME LIKE 'DEL%'
ORDER BY
NAME DESC
FETCH FIRST 20 ROWS ONLY
) AS TMP
ORDER BY
TMP.RUNNING_NO ASC
FETCH FIRST 10 ROWS ONLY
but I know it's bad style. So, how to query for highest performance?
