Hash file Create, delete file and Clear file Options

[shrinivas]

Hi Guys, I have a confusion about how to use Clear file, delete file and Create file options for a Hash file. My confusion is which combination of options gives me better performance each time I run the jobs.
My most requirements are like to clear the hash file before writing.
So shall I tick the Create option and delete option to do the need full or shall I only check out the clear file option for better performance. Or shall I check all the options. I have observed that for the first run of the job with out checking the Create option for the hash file, the file creates by default. If I tick the create fiel option for each run , so DS creates the hash file for each run or just overites the existing file?

Please guide me guys .

[ray.wurlod]

Once the hashed file is created, unless you need to change its shape, you don't need to create it afresh every run; clear file is very fast and will suffice. Conversely, if you do create the hashed file, clear file is a waste of time.

[chulett]

If I tick the create fiel option for each run , so DS creates the hash file for each run or just overites the existing file?

Checking the 'Create' option just gives you the opportunity to override the default creation values. The only way those get applied 'each run' is if you also enable the 'Delete' option. The hashed file will always be created if it does not exist regardless if the 'Create' option is checked or not.

And if you do Delete and Create each run, the Clear option is wasteful and would be like dropping and recreating a database table and then immediately issuing a 'truncate' command.