Sun Java System Portal 7 community features uses derby database on its backend to store community features in Portal. One may use an opensource client like Squirrel SQL Client from your desktop to connect to the Derby database. My main intention here is to identify the connection variables required to connect to the database.
Client : Squirrel SQL Client v 2.3.
Download site : http://squirrel-sql.sourceforge.net/
Install using -- java -jar squirrel-sql--install.jar
Add jdbc derby driver to squirrel client lib directory.
Driver : derbyclient.jar
Load location : C:\Program Files\SQuirreL SQL\Client\lib\derbyclient.jar.

If the jdbc driver is correctly loaded, then 'Drivers' window should show a 'Tick' mark against Apache Derby Client.

Click on '+' sign on Alias window to create a new connection configuration.
Enter an alias name - 'Portal Derby'
The driver selected should show Apache Derby Client
URL : use the JDBC connection string
Database port : communitymc_portal1 (communitymc_portal1 is the database name)
Database port : 1527
User name : portal
Password : portal
click on Test to test connectivity.
On the top left corner, select Connect to 'Portal Derby' from drop down.
Tables should show up Portal Derby > Portal > Table