The only fields that are required to be defined in a DBD are the keys, indexed fields, and any other fields that the application wants to be able to reference in Segment Search Arguments (SSAs). In the IMS system I work on, the 99% of the segment fields are not defined in the DBD.
And even if they are, IMS is limited to 8 character field names, with only a few field types. In our system we only define fields as binary or "X". X fields could be packed decimal, zoned decimal, or alphanumeric. They could hold dates. If they're numbers there could be an implied decimal point. There could be a sign, or it could be unsigned. None of that can be determined from the DBD. Do you have access to any IMS tools beyond what's included in the IMS base product? For example, if you have the Broadcom IMS tools... * You can unload a database from an image copy. That is, create the unload format file from an image copy input * The Database Organizer Extractor can create a flat file from a database, which /in some cases/ is a lot easier to process than an unload file. If you have File Manager/IMS, it can create an extract file that includes the concatenated keys to each segment. That also can be easier to process than an IMS unload. -----Original Message----- From: IBM Mainframe Discussion List <[email protected]> On Behalf Of Jason Cai Sent: Friday, May 17, 2024 3:21 AM To: [email protected] Subject: Re: Assistance with Converting IMS DB to MySQL DB Dear Andrew, Thank you for your suggestion. I have some thoughts on the IMS segment layout and defining SQL columns, and I’d like to confirm with you: If I have the DBD (Database Description), is it sufficient to correctly define the SQL columns? Or do I need the application copybook in addition to the DBD? If the SQL columns are defined correctly, is it possible to do the following: a. Unload Data from IMS using PGM=DFSURGU0 b. Define DB2 Tables c. Load Data into DB2 using PGM=DSNUTILB The above are some of my ideas, and I’m not sure if they are correct. I hope to get your guidance. Thank you very much for your help! Best regards, Jason Cai ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to [email protected] with the message: INFO IBM-MAIN ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to [email protected] with the message: INFO IBM-MAIN
