How big should a file be to use REORG or OLREORG?

Document ID : KB000093304
Last Modified Date : 30/04/2018
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Question:

What is the minimum number of records a file should have that would make it worthwhile to perform an OLREORG  or REORG instead of DBUTLTY BACKUP and LOAD?
I have an almost static file with only 10,00 records. Is it worth to use OLREORG?

 

Answer:
For small areas we do not recommend to use the OLREORG or REORG utilities.
Use DBUTLTY BACKUP and LOAD instead.
An area with 10,000 records would be considered to be small.

DocOps section When to Use REORG has some information on this which also applies to OLREORG:

REORG is best used with large areas that contain large amounts of data. We do not recommend using REORG to process small areas. For small areas, use the normal BACKUP and LOAD functions of the CA Datacom®/DB Utility (DBUTLTY). Areas of medium size can best be reorganized by using the BACKUPONLY option of REORG to perform a fast parallel backup, followed by the resulting 1-25 files used as concatenated into a single LOAD function.

The main benefit of using OLREORG is that you can reorganize the Datacom file without having to take it offline. If you have scheduled MUF downtime which allows sufficient time for a BACKUP/LOAD or REORG to run then you would use these instead. REORG is the fastest but it does require the database be unavailable for update when it runs. OLREORG would typically be used for large databases where you don't have sufficient downtime to do a BACKUP/LOAD or REORG.