Mithun Kulkarni

sravani gogineni wrote:Hi


When the sessionID is stored in cookies the same session is shared among multiple windows/tabs that we open.
So, once we log out from any of the windows and the session ends here. When we re-login , a new session is created.
Now if i submit a form in the open of the opened windows of previous session , the form cannot retrieve all the data from the session object since it overides the new sessionid to the old session id when you click submit button.

So we need to use some hidden variable in the jsp and store the old session id. Compare this value to the new session id and if they are different , show an error page that session is expired.

While showing the error page, do you need any of the data saved in the HTTPSession? If not then you can think of handling that condition where the HTTPSession is null in your action and forward it to an error page.

The migration will be run couple of times. Once to migrate all data once to Oracle and then to migrate any differential data for a period of couple of weeks.

Jeanne Boyarsky wrote:Mithun,
I would use the ETL tool. It's a lot of data to move and an ETL tool is going to be better optimized than something you write.

Thanks for resply Jeanne,
But what I think is an ETL does simple things in a faster way. In my case, I need to read a row from DB2, then load the XML blob, then parse the XML to convert it into a simple XML, then map the xml elements to table columns. So when I have these steps in my migration, then I may need to build custome components for ETL.
So don't you think building a java tool will be better in this case?

As pointed out by Satish there is problem with your NRIC value. You need to parse the value from the input file and strip it to fetch only the number from that value.
Then it should work without any further change.

Hi,

In my current assignment we are planning to migrate data from DB2 to Oracle. Currently the data is stored in the form of a XML blob in DB2. However we have designed a relation data model in Oracle to store the same data (which was stored as a XML blob in DB2).

We are also introducing JPA layer for persistence to store and retrieve data to/from oracle.

I have around 50 million records in DB2 in the form of XML blob. Now I want to move this data to Oracle (in a relation db model- each entity stored in a seperate table).

I want to know which of the below approaches I should follow to do this data migration:

1. Use an ETL tool. My company has Ab Initio license, so I can use this ETL tool.[I do not have experience, but will be eager to learn].

2. Build a new tool using Java for this migration. As I had done a POC on using JPA for persisting and retrieving entities, and the JPA mappings is already there, I can reuse some of this code. And some additional processing which needs to be done in approach 1 can be avoided. [Additional processing : mapping entity to database, processing XML blob and reading its content]

So please help me in making this decision with supporting points.

Thanks in advance,
MK

Freddy Wong wrote:Encode the two BLOBs into Base64 and do the String comparison on those encoded Strings.

Thanks for the reply.
Here the object model is stored as Blob only in source database, where as in destination the object model has a relational data base model. And each entity is saved inn its table.
So I dont think I can directly use this approach.

Thanks,
MK

Hi,
I have a requirement in my project to migrate data from one database to another database (a different one). I am planning to build a data comparison tool, which will compare the data between source and destination DB.
I am using JPA implementation of Eclipselink in my application.
I want to know which of the below approaches is better :

Approach 1: Read data from source DB(stored as XML blob) into an object model (contailing entities) and then read data from the destination DB(stored in distributed relational manner) into a new Object model. The compare the two object models. Here I can override equals() in all my entity classes and use Apache commons library to compare the object models.

Approach 2: Read data from the source DB which is an XML, then read data from destination and build an xml out of it. And then compare these 2 xmls and report the differences.

So is there any other better approach to achieve my requirement?
Please help.

Thanks in advance,
MK

I have used Jprofiler and its really worth buying. It has different views (memory, CPU, Threads) which will help you identify performance problems.
You can also configure the tool to profile from memory perspective or from the performance perspective.
If you are looking for open source profilers, now many IDEs come with their own profilers so you can give it a try to profile using the one which comes with your
IDE or select one from the link posted earlier.

Hi,
I have developed a web service using Axis2. And My service operation accepts org.apache.axiom.om.OMElement as the input parameter.
I have a question as to whether to use toString() or toStringWithConsume() on OMElement object.