Record Definition Language › Determining the Best Compression › How to Enter or Change the RDL Using the IUI

How to Enter or Change the RDL Using the IUI

Before actually implementing a data set, you can devise different RDL specifications in order to achieve better compression. To devise these specifications, you must update the RDL for a data set and then run a trial compression job. Detailed instructions on how to update the RDL follow.

1. Select Maintenance from the Task menu.
2. Select Analysis File to display the Analysis File Maintenance menu.
3. Select All Records or Limit Search.
   • All Records displays a list of all the data set names that are in the Analysis File.
   • Limit Search displays the Data set Name selection window. Type the data set name for the search, and press [Enter] to see a list of the data set names you selected.
4. Move the cursor to the Action field next to the data set you want.
5. Type R, and press [Enter] to display the RDL User Parameter Maintenance screen.

   Initially, each noncompressible field (type N) represents 1 or more keys. The definition for the N fields cannot be shortened or eliminated but can be increased in length to cover more data. Consider doing this if, for example, there is one byte between 2 type N fields. The other fields can be altered as needed. Any altered definition must not alter the total length of the definition as this can change the offset of the type N fields and thus the key positions, causing the Dialog to reject the RDL. You can now enter the RDL for the compressible area.

6. Enter up to 12 lines of 78 characters each for the data set's RDL. When all changes to the RDL are made, press [Enter] to store the new RDL. If you need to cancel the changes you made in the RDL, press the [End] PF key, which returns you to the Analysis File Maintenance screen.

   If you have made any errors in the RDL, an error message is displayed in the upper right-hand corner of the screen and the cursor appears at the location of the error. To obtain more information about the error, press the [Help] PF key. Correct the error in the RDL and press [Enter].

   When the RDL is correct, it is recorded and you are returned to the Analysis File Maintenance screen.