Re: Data extractor for IMS,DB2,VSAM

In article <1992Jun01.103504.172628_at_ipgaix.unipg.it>, luca_at_ipgaix.unipg.it (Luca Priorelli) writes:
|>
|> Quoting from a product description (from Unisys):
|> "Open/OLTP addresses the requirement to access mainframe databases based
|> on proprietary OLTP architectures. With Open/OLTP Extract products
|> data can be accessed from mainframe databases [..] IBM's IMS, DB2, and VSAM.
|> The data can be automatically loaded into Informix or Oracle RDBMSs.
|> This allows applications and/or users to access mainframe data, and
|> move it into their applications."
|>
|> I am looking for some other products like this, that allow to access
|> data from IBM's mainframes, but more flexible than this and
|> not so Unix/Unisys dependent.
|> Luca Priorelli

There is a relatively straightforward programmatic way of accessing DB2 data and you can pick up details from the appropriate IBM documentation.

For VSAM data, you really have to know a bit about the data you're trying to extract and the format of the data. Assuming you have the necessary security privileges for the file, you can write code to OPEN/READ/CLOSE the VSAM cluster. There is nothing I know of which supports arbitrary download of data from VSAM, other than standard IBM utilities (UNLOAD etc).

For IMS, you're really out of luck because the only way you can access IMS data is via a transaction (MPP/WFI/BMP). Your program must know the physical details of the data segments you plan to access and the program has to be loaded (together with the appropriate PSB's) into IMS libraries.

Basic story is...

DB2 has a catalog which supports random queries (what data is defined?, what are the column names? data types? and so on). You can take a ramble through and select what you want - although this isn't encouraged.

For IMS and VSAM, you really have to know a lot about the data you want, PLUS, you have to know what you're doing. There isn't any "easy way".

Sorry.

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