We have recently purchased Oracle (I'm totally out of the loop), running on an NT box. The current plan is to collect data on ADABAS, enhance the data there, and then move it to an Oracle database(s) for end-user use. It wasn't long before the question arose, "Why should we keep two different database technologies?" I can see the day coming when a choice will be made. I know I am biased, so I'll keep my opinion to myself. What I need is objective information comparing ADABAS and Oracle, the relative pros and cons of each, as well as a heads up on things to watch out for/tips on migrating data back and forth between the two databases. For what it's worth, performance is an important issue here. So, I would appreciate a reply from SAG-Lers with experience in both DBMSs. If you can backup opinions/experiences with objective material (stats), that would be most useful.
ADABAS is relatively simple and easy to administer. Oracle, the base product, is more complicated and difficult to administer. Everything is done through SQL. At first this is very frustrating, but eventually you get comfortable with it and like the consistency of it. There are also plently of readily available tools to reduce the amount of SQL you type.
During a query, the heart of ADABAS is CB,SB,FB,RB..... the heart Oracle is SQL.
My experience on ADABAS tends to view it as primarily sitting on one machine. My Oracle experience views it as a network. To me this is Oracle's true strong suit. The one experience I like to cite is using a 'wizard' to build an Oracle database on an NT machine and adding that database to the network. In 15 minutes I had a database that could be accessed by any user on the network (provided they have the correct security). Behind the scenes the end user doesn't know where that database is. This can lead to performance headaches in that suddenly hundreds of user's are pounding on a little NT box. It's up to the administrator to use the proper hardware in the proper places. The point is, seamless network integration is inherently part of Oracle and I haven't seen that demonstrated in ADABAS.
Performance. ADABAS is fast, but I wouldn't say Oracle was a dog. In the original posting, one database is on an NT box, the other I assume is a mainframe. No comparison, ADABAS is faster. As with any database, if you understand the how the data is being accessed, and you know how to alter the database to improve performance, then it will perform well. The limitation being processing power. Raw stats don't tell you if the database is setup properly. My general feeling is that if you compared a simple query that brought back any 5000 rows/records with 50 columns/fields from 1 table/file in Oracle and ADABAS, then ADABAS would perform better. I tend not to think that's enough to tell me how it will perform in the real world.
Also most ADABAS calls go against 1 file. With Oracle, data tends to be more normalized. All my Oracle training teaches the Entity Relationship theory. I've never fully understood the true value of normalized/relational data in business applications. But generally I see Oracle as broken into multiple tables (files). Perhaps if I understood relational theory better I'd have a better appreciation for it. All I can say is that all the slow running Oracle queries I've seen have multiple (6+) table joins in them. However I do think that Oracle is better suited to handling the joins.
ADABAS has no concept of referential integrity. Oracle constraints also do a better job of preserving data integrity. It's part of the database, you don't have to rely on the programmer.
This leads to moving data between databases. I've not encountered any problem here. I've generally only dealt with it on a raw data level. I.e. tell ADABAS to give me raw data then Oracle can load it in. Or same thing the in opposite way. ASCII/EBCDIC is generally a simple issue to deal with. I don't have any experience with the 2 databases talking to each other.
SAG has Natural. Oracle has PL/SQL although they're pushing JAVA a lot these days. Natural is king.
I could go on, but I've spouted off enough. I do like ADABAS, it's reliable, simple and fast. I also like Oracle it has very many features and has a lot of potential power. It depends on what your needs and desires are as to which you should use. Hope this has been of some use.
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