core and temp files

I've got a sudden hard disk space problem that appears to be related to
core and pg_sorttemp2761.2  like files in the base/database directory.
Can these be deleted with no ill effects?  I removed one core file
higher in the directory structure with no ill effects.

What's causing this?  I could set up an automatic deletion program if
necessary.

--
Tom Bakken
Information Resource Manager
USDA, Rural Development
101 South Main, Suite 102
Temple, TX 76501

Phone: 254-742-9726 Fax: 254-742-9709
Email: tom.bakken@tx.usda.gov