Re: Export and Import Utility

Hi!  

Interesting scenerio...it would be awfully sl-o-o-w. In response to your questions;  

(1) Yes, you should be able to launch the export utility from within your application program providing that you also pass or specify all of the required parameters for the export to be performed. (same is true for import) I would suggest, passing the parameters to a VMS .COM file and executing the .COM file from within the application. In order to write to the tape...you would have to ensure that the device was always in a readied state..that meaning that there is always a tape in the drive and that the device has been ALLOCATED to the user who will be wanting to write to it.  

From the scenario that you have painted...it looks like you are hurting for disk space... It would be helpful to know whether the USER will be repeatedly archiving files to the tape...or will they be only exporting one file. If there are going to be multiple exports on a tape..you are going to run into problems with identifying which export file to retrieve for an import..and possibly running out of space on the tape...what is going to happen if they have to mount additional tape volumes?     

If it is only one file at a time...I would launch a VMS command procedure from within your application..perform the export to disk...(it's faster)...then copy the file to the tape...delete the disk file..and REWIND the tape...within the same command procedure..that way...it's ready for a retrieval. LAUNCH THIS PROCEDURE IN BATCH...   When the USER wants to import...launch a VMS command procedure from within your application that copies the .DMP to disk and imports the .DMP into SEPARATE ARCHIVE TABLES...don't load directly into your production tables...you could overwrite current data and corrupt your database...definitely allocate separate tables for a historical archive retrieval...I am assuming that they only want to look at the older data..not make it the current database data.  

I don't see why you can't pseudo use the tape like a disk...as long as you are aware that you have to rewind the tape in order to read back off of it. I don't think it's is a solid solution to a production application problem...but I don't know what the whole situation is.  

I suppose it is also possible to implement this solution if they were going to be doing multiple exports to the same tape...but the solution will get a bit trickier because you will have to keep track of the names and savesets of the different exports. I would create a database table to contain and track these.  

Hope this helps.... Sandra Fergusson Received on Sun Jun 11 1995 - 00:00:00 CEST