User can access DBS in two ways now.

1. Web interface: https//cmsweb.cern.ch/dbs_discovery/

2. Command line client (from a CMSSW scram area):

source /grp/cms/tools/dbs_client/setup.sh

dbs search --query='your query' 

Some example query to get the dataset names

#find RAW datasets
dbs search --query='find dataset where dataset like *cosmics*'
--url=http://cmsdbs.rcac.purdue.edu:8090/DBS/servlet/DBSServlet

#find RECO datasets
dbs search --query='find dataset where dataset like *cosmics*/RECO'
--url=http://cmsdbs.rcac.purdue.edu:8090/DBS/servlet/DBSServlet

#find Express datasets
dbs search --query='find dataset where dataset like *Express*CRAFT09*'
--url=http://cmsdbs.rcac.purdue.edu:8090/DBS/servlet/DBSServlet

#find datasets containing events from run number 108741
dbs search --query='find dataset where run = 108741'
--url=http://cmsdbs.rcac.purdue.edu:8090/DBS/servlet/DBSServlet

#find latest 10 files from Express Reco
dbs search --query='
find run,file,file.createdate where dataset = /ExpressMuon
/CRAFT09Expressv1/FEVT and file.createdate > 20090728
order by file.createdate '
--url=http://cmsdbs.rcac.purdue.edu:8090/DBS/servlet/DBSServlet 
| tail n 10

#find for a given dataset the files of a given Run:Lumi
dbs search --query='
find file where dataset = /ExpressMuon/CRAFT09Expressv1/
FEVT and run=109011 and lumi=19'
--url=http://cmsdbs.rcac.purdue.edu:8090/DBS/servlet/DBSServlet

#find for all datasets the files of a given Run:Lumi
dbs search --query='
find file,dataset where run=109011 and lumi=19
--url=http://cmsdbs.rcac.purdue.edu:8090/DBS/servlet/DBSServlet