As I recall, the Dec product was called Rdb, and generally regarded as quite good. It was subsequently bought by Oracle.
The old hierarchical and network systems did not require foreign keys, because all records were explicitly linked via hard-coded pointers. So you HAD to get your design right before building the data model, otherwise retrieval would be a nightmare. Because relational systems allow joins at query time, a major slackness has crept into database model design. Like not always protecting the integrity of PKs... Talking of working on small memory machines - here is a test for your age in the industry - all those who can remember writing overlays stand up! I suspect the current crop of PC software engineers have never encountered overlay programing. peter edinburgh > -----Original Message----- > From: Mercadante, Thomas F [mailto:[EMAIL PROTECTED]] > Sent: 25 June 2002 15:08 > To: Multiple recipients of list ORACLE-L > Subject: RE: Difference Between DBMS/RDBMS > > > Oh you bunch of young whipper-snappers! > > A long time ago in a place far-away, we started with simple > File Systems. > Then came ISAM file systems. > These begate DBMS systems. Note there was no 'R' in original > DBMS systems. > Some of these were simply an extention to ISAM files that allowed (and > demanded) a more formalized collection of files. In these > files, there were > tables and indexes and primary keys. I remember these as > "Hierarchical > Database Systems". Still no such thing as foreign keys. > > Finally, I believe, DEC came out with the RBMS system which > was (I know I > will be corrected on this) one of the first Relational > Database Managment > Systems to be made available for large systems. (I have no > knowledge of IBM > products - anybody? When did DB2 make itself known?). > > On PC's there was also something called RDB I think. > > See, its good to be old! > > Tom Mercadante > Oracle Certified Professional > > > -----Original Message----- > Sent: Tuesday, June 25, 2002 8:24 AM > To: Multiple recipients of list ORACLE-L > > > i give up the R, is that the difference? > > joe > > > Santosh Varma wrote: > > > could any body point me the difference(s) between DBMS and RDBMS ?? > > because in DBMS also as in RDBMS, we can related two or more > > tables..if a column exists in another table for relation ?? > > > > Thanks and regards, > > > > Santosh > > > > > -- > Please see the official ORACLE-L FAQ: http://www.orafaq.com > -- > Author: Joe Testa > INET: [EMAIL PROTECTED] > > Fat City Network Services -- (858) 538-5051 FAX: (858) 538-5051 > San Diego, California -- Public Internet access / Mailing Lists > -------------------------------------------------------------------- > To REMOVE yourself from this mailing list, send an E-Mail message > to: [EMAIL PROTECTED] (note EXACT spelling of 'ListGuru') and in > the message BODY, include a line containing: UNSUB ORACLE-L > (or the name of mailing list you want to be removed from). 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