i have doubt that if we want to use different database for each portlet then we need to update values in portal-ext.properties file in tomcat home path . but don't it conflict with actual liferay portal database?? i want to know how it works.
For out of the box portlets, it's not supported. If you want to do it for your own custom portlets, there's a "data-source" attribute you can set in service.xml. Please refer to the liferay-service-builder DTD file for more info.
