> > There are 3 different code platforms for DB2 - I'm missing > > some details, so someone please fill in the blanks... > > > > - Non-mainframe platforms (Unix-type), which came from > > another data base product > > purchased by IBM a long time ago (Sequent?), and has some > > code shared with > > Informix > > - z/OS (the original System R) > > - z/VSE, z/VM, which IIRC is based on DL/1 > > IIRC, DL/I "maps" to IMS.... On VM/ESA (previous shop; many moons ago) > we ran "SQL", which probably "maps" to DB2 on z/OS. I think it was also > called "SQL" on VSE.
The first IBM relational product was SQL/DS which ran on VM. System/R was the original research prototype and it never shipped to the outside world. DB2 was developed independently of SQL/DS and it had a completely MVS-centric design that could never have fit into any other IBM mainframe OS. I don't know if SQL/DS ever ran on VSE, but I am certain that DB2 never did. DL/1 (data language 1) was and is the interface language for IMS/DB and its successors. It supports access to hierarchical parent/child data structures with verbs like Get Unique (GU), Get Next (GN) etc. The DL/1 model is wildly different than any SQL dialect. It is true that there are separate code bases for the z and non-z forms of DB2, but as time passes most new functions are added to the open platforms first and wherever possible that code is shared with DB2 on z. CC ---------------------------------------------------------------------- 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
