SharePoint 2010 Crawl DB Issue

Hi All,

I have issues with SharePoint 2010 crawl database. The DB size is too large, now the size is 300GB. 
How to control the Crawl DB growth ?

As of now i have created a new crawl component and crawl db. Can i delete the old crawl component and DB ?
Please suggest me.

Thanks & Regards,
Sankar