yumError

[designer]

rpmdb: Program version 4.8 doesn't match environment version 5.1
error: db3 error(-30971) from dbenv->open: DB_VERSION_MISMATCH: Database environment version mismatch
error: cannot open Packages index using db3 - (-30971)
error: cannot open Packages database in /root/.rpmdb
Traceback (most recent call last):
File "/usr/bin/yum", line 29, in <module>
yummain.user_main(sys.argv[1:], exit_code=True)
File "/usr/share/yum-cli/yummain.py", line 315, in user_main
errcode = main(args)
File "/usr/share/yum-cli/yummain.py", line 159, in main
base.getOptionsConfig(args)
File "/usr/share/yum-cli/cli.py", line 189, in getOptionsConfig
self.conf
File "/usr/lib/pymodules/python2.6/yum/__init__.py", line 723, in <lambda>
conf = property(fget=lambda self: self._getConfig(),
File "/usr/lib/pymodules/python2.6/yum/__init__.py", line 249, in _getConfig
startupconf = config.readStartupConfig(fn, root)
File "/usr/lib/pymodules/python2.6/yum/config.py", line 807, in readStartupConfig
startupconf.releasever = _getsysver(startupconf.installroot, startupconf.distroverpkg)
File "/usr/lib/pymodules/python2.6/yum/config.py", line 914, in _getsysver
idx = ts.dbMatch('provides', distroverpkg)
_rpm.error: rpmdb open failed


What can I do ?