I supported ADABAS for 2 years about 20 years ago. What I remember was the SVC that modified itself and still running with 24 bit addressability. Don't get me wrong - I could write amazing programs in Natural in just a couple of hours but the other restrictions were painfull. Went on an interview for a DB2 job and discovered they still had ADABAS - asked how they managed it - basically they created a new ADABAS collection for every application area that wanted it. You have to backup the entire database - can't select one application and create a backup point.
Started working as IMS DBA with 1.1.5 - I think - been applications, system DBA and sysprog. Never did past path but all combinations of HDAM, HIDAM, SHISAM, etc It is very difficult to beat the performance of a properly designed HDAM application unless the users require a half dozen secondary indexes. Problem was the 2G/4G dataset limit - IBM didn't release partitioned database until V9. Yes, you could move segments to a separate dataset (max of 10) but it created performance problems as often as solving them. People did all kinds of unusual design work to support more than 4G of data. One place had a dozen PCB's that were selected by application based on key range. first supported DB2 as sysprog on 1.2. My mistake of being in the IMS group and saying it isn't that hard - just another database -setup 1,2,3 write a userid exit and let the applications groups go. SQL is different. It requires a different type of design. I think it is harder to build a good SQL design than IMS because you have so many choices and the SQL hides the performance impact of those choices.The ability to use big bufferpools can also hide bad design. It can still meet response time goals but use more resources than it should. The other part is that DB2 started with a 64G limit and has expanded that multiple times. ADABAS does use less memory and disk space than DB2 but it doesn't scale to really large applications the way DB2 does and it doesn't let you keep the database up while some portion of the database is having utilities run. Mike On 10/7/07, Itschak Mugzach <[EMAIL PROTECTED]> wrote: > > I spoke few days ago with an ADABAS specialist that claimed that ADABAS is > much faster and has low overhead compared to IMS and DB2. Is this true? > > Itschak > > ---------------------------------------------------------------------- > 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 > -- Mike ---------------------------------------------------------------------- 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
