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Joe, What about scalability of applications using record level access?! Isn't it true, that every process needs it own AS/400 Object for the requests to the database? What about transaction handling!? Isn't it true, that it's more complicated wih rla compared to sql (similar situation in rpg rla versus embedded sql)? What about application design?! Isn't it true, that you will find all key relations of your database in your application logic, like in rpg programs using rla? What about using EJBs?! Isn't it true, that you can't use Container managed persistence with RLA? What about Java standards and proven best practices?! Isn't it true, that only very very few people use rla to access the as400 database from a java application compared to the rest of the world using JDBC to access relational databases? What about surviving critical reviews of customers?! Isn't it true, that you will come in trouble in every review of third parties. What should I answer to the question - why don't you use proven technics? What about maintainability of the application?! Isn't it true, that you will have problems to find people who understand the code? Summary of all: If the situation of the as400 is that we would have to use RLA to match the performance requirements, then the as400 will be a (very) nice rpg machine and java applications will run on other platforms using other database servers. Dieter PS: And I would have to make a decision, wether I want to write rpg programs or I have to change the platform because I prefer java. On Wednesday 26 March 2003 15:33, you wrote: > > From: Suresh Kumar > > > > Couple of observations: > > 1. Even with all these steps, response time of 20 seconds is not > > acceptable. We are continuing to improve the code. We do have > > about 20 SQL statements to get data from various tables (all > > tables are small) and then the HTML is created and sent to > > client. Is 20 seconds response acceptable?? > > The AS/400 database, DB2/UDB, is not a purely relational database. While > it supports a very robust SQL interface, it also has a faster underlying > access method. And since JDBC is basicallly a Java wrapper around SQL CLI > access, JDBC is typically not the fastest access method. There are two > other methods to access data that tend to be faster. > > One is the Record-Level Access methods of the toolbox - look for KeyedFile > and its various methods. These allows you to directly access individual > records in a table (file) very quickly. > > Second is to write a small RPG program to return the data. This program > can be called repeatedly to return the records in a data structure, which > can then be parsed in the Java program. This technique is very fast as > well. > > > 3. The same setup with Oracle as back end seems to run much > > faster (within 5 seconds). Is this generally true?? > > No, nothing is "generally" true about Oracle and DB2/400. Oracle is > designed around SQL, and it typically requires a large amount of tuning. > It may be that your particular Oracle database is well tuned for the > queries you are making. But in any event, this is as fast as Oracle is > going to get - you have no other options. On the other hand, you can > dramatically improve your DB2/400 access by using native I/O techniques - > techniques which are not available to the Oracle programmer. It means that > you will have to understand how the AS/400 database works, and it will > require extra programming, but in the end, you get what you pay for. If > you want one piece of code that runs everywhere, chances are it's not going > to run particularly where ANYWHERE. > > Joe > > _______________________________________________ > This is the Java Programming on and around the iSeries / AS400 (JAVA400-L) > mailing list To post a message email: JAVA400-L@xxxxxxxxxxxx > To subscribe, unsubscribe, or change list options, > visit: http://lists.midrange.com/mailman/listinfo/java400-l > or email: JAVA400-L-request@xxxxxxxxxxxx > Before posting, please take a moment to review the archives > at http://archive.midrange.com/java400-l. -- mfG Dieter Bender DV-Beratung Dieter Bender Wetzlarerstr. 25 35435 Wettenberg Tel. +49 641 9805855 Fax +49 641 9805856 www.bender-dv.de
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