MOSS 2007 after deleting second stage recycle bin, no change in db server disk space?

Hi

We are running MOSS 2007 with SQL server 2005 .

I deleted second stage recyclebin items for my site collection but didnt get any free space in the disk drive of db server.

I came to know that sharepoint allows to execute delete command in the db server but not truncate which will not free up the disk space.

Then, how could we get the free space in the server to continue the business operations on the site without adding new disk space to the drive?

 Should i follow up the DBAs to shrink up the files in the sql server?

Should I shrink the log files enough or content too?

Thanks,

Anil

ANIL