[JDBj-SPEC DATA SOURCE] and JDBJ.ini

The [JDBj-SPEC DATA SOURCE] section in jdbj.ini will decide whether the serialized object tables [F989998,F989999] have to be read from OCM or a overridden one.

1. If the total section is commented out, then these tables are read from the dataSource specified by the OCM mappings.
2. If the name given for the field 'name=' matches a datasource in the Datasource master table[F98611],then other details like the database type, database name,TCP/IP port etc are fetched from the dataSource master table.
3. If the name doesn't match any existing datasource, then the properties are read from the other fields mentioned in the section[JDBj-SPEC DATA SOURCE].

Example1:
#[JDBj-SPEC DATA SOURCE]
#name=System - 812
Here the section is commented.So OCM will be used

Example2:
[JDBj-SPEC DATA SOURCE]
name=System - 812
databaseType=I
server=HPISER1
Here suppose 'System - 812' matches an existent datasource in DataSource master table, then the rest details are read from there.This is just for flexibilty and to reduce possible errors we make when the datasource details are entered manually.
If the 'name=' doesn't match any datasource in the F98611 table ,what you have filled in the rest of the section matters.

Troubleshooitng the SQL Connectivity issues : Steps to start with

http://blogs.msdn.com/sql_protocols/archive/2008/04/30/steps-to-troubleshoot-connectivity-issues.aspx

SELECT FOR UPDATE and NOWAIT

SELECT FOR UPDATE[SFU in short] in Oracle lets you lock the records satisfied by the Where clause in advance.By default when you issue this command it will wait indefinitely for the locks.So if someone has already locked a record, you will never get the control back.
On the other hand if you include the optional keyword NOWAIT, the control will immediately come back to application, if the record is locked by some one else.

Useful JVM Links

Java Virtual Machine Specification

Easy way to modify/edit unix files directly from windows

If you are new to unix operating system ,modifying the files using vi is difficult, atleast in the begining days.Here is an easy way to edit the unix files directly from windows.
1]Open your EditPlus editor.
2]Go to File->FTP->Ftp Settings
Here add an account to your unix machine:Name of the unix machine,user with which you login,password and the path.This step is required only once
3]Once you are done with step2, go to File->FTP->Open Remote
Select your account and click browse.Navigate to the required file and open it.Now edit the file and finally save it.This way you can forget the painful way of editing via vi.
I didn't face any issues while compiling the files edited using the method.If you come across any, please comment here.