Application Design and Tuning for Performance › Search Strategies › Name Searching › Probing the Table Twice

Probing the Table Twice

The following example gets better index access, but it will probe the table twice.

SELECT PERSON_ID
FROM   PERSON_TBL
WHERE  LASTNAME = 'RADY'
AND    FIRST_NAME = 'BOB'
UNION ALL
SELECT PERSON_ID
FROM   PERSON_TBL
WHERE  LASTNAME = 'BOB'
AND    FIRST_NAME = 'RADY'