Lindy, You can access a VSAM Linear dataset with VSAM. All a linear dataset really consists of is 4K blocks of unformatted data. The application reading the data would have to know how to handle the pages and do the de-blocking themselves. For instance, DB2 (since DB2 2.2 I believe) has used LDS's for the tablespaces and indexspaces. However, as was mentioned by Binyamin, DB2 uses the Media Manager, which is a lower level I/O driver than that used by native VSAM macros. However, using native VSAM you can access LDS's with MACRF=ADR or CNV on the OPTDCE. With ADR, the RBA passed as the key has to be on a 4k boundry. I believe that CNV is used when sequentially reading the LDS (it has been quite a while since I have worked with this).
Wayne Driscoll Product Developer JME Software LLC NOTE: All opinions are strictly my own. -----Original Message----- From: IBM Mainframe Discussion List [mailto:[EMAIL PROTECTED] On Behalf Of Lindy Mayfield Sent: Sunday, August 05, 2007 5:38 AM To: [email protected] Subject: Re: VSAM Linear Dataset n00b question Great, thanks for the hint. Problem solved. I was looking in the wrong bookshelf. | A linear data set is processed as an entry-sequenced data set, with | certain restrictions. Because a linear data set does not contain control | information (CIDFs and RDFs), it cannot be accessed as if it contained | individual records. You can access a linear data set using these | techniques: * | VSAM * | DIV, if the control interval size is 4096 bytes. * | Window services, if the control interval size is 4096 bytes. I assume the 4th method is to go directly to the media manager layer. I assume from what you said about cost that it is a set of API's or something that must be purchased separately. I didn't find much about it through Google. Thanks, Binyamin, for helping me clear that up. ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to [EMAIL PROTECTED] with the message: GET IBM-MAIN INFO Search the archives at http://bama.ua.edu/archives/ibm-main.html
