Hash file: Selecting all/few columns: Performance Impact
Posted: Mon Aug 02, 2004 3:35 pm
We have a hashfile containing 5 columns. Job 1 and Job2 use this hash file for reference lookups.
Building two hashfiles instead of one common hashfile is not an option available to us.
Job 1 uses 4 columns of the Hashfile and job 2 uses 2 columns of the Hashfile.
As of now for both jobs, while importing the Hashfile definition, we have imported all 5 columns comprising of the key.
My question is can I use only the required columns from the hashfile for each job. i.e. for job 1 use only the 4 columns required, for job2 use only the 2 columns required.
Does this improve performance, degrade performance, no impact on performance?
Building two hashfiles instead of one common hashfile is not an option available to us.
Job 1 uses 4 columns of the Hashfile and job 2 uses 2 columns of the Hashfile.
As of now for both jobs, while importing the Hashfile definition, we have imported all 5 columns comprising of the key.
My question is can I use only the required columns from the hashfile for each job. i.e. for job 1 use only the 4 columns required, for job2 use only the 2 columns required.
Does this improve performance, degrade performance, no impact on performance?