Guys,

If you getting this error in your server while using yum or rpm command.

---------------------
rpmdb: PANIC: fatal region error detected; run recovery
error: db4 error(-30977) from dbenv->open: DB_RUNRECOVERY: Fatal error, run data base recovery
error: cannot open Packages index using db3 - (-30977)
error: cannot open Packages database in /var/lib/rpm
Traceback (most recent call last):
File "/usr/bin/yum", line 29, in ?
yummain.user_main(sys.argv[1:], exit_code=True)
File "/usr/share/yum-cli/yummain.py", line 309, in user_main
errcode = main(args)
File "/usr/share/yum-cli/yummain.py", line 157, in main
base.getOptionsConfig(args)
File "/usr/share/yum-cli/cli.py", line 187, in getOptionsConfig
self.conf
File "/usr/lib/python2.4/site-packages/yum/__init__.py", line 664, in <lambda>
conf = property(fget=lambda self: self._getConfig(),
File "/usr/lib/python2.4/site-packages/yum/__init__.py", line 239, in _getConf ig
self._conf = config.readMainConfig(startupconf)
File "/usr/lib/python2.4/site-packages/yum/config.py", line 804, in readMainCo nfig
yumvars['releasever'] = _getsysver(startupconf.installroot, startupconf.dist roverpkg)
File "/usr/lib/python2.4/site-packages/yum/config.py", line 877, in _getsysver
idx = ts.dbMatch('provides', distroverpkg)
TypeError: rpmdb open failed
---------------------

Solution is ::
--------------

rm -f /var/lib/rpm/__db*
/usr/lib/rpm/rpmdb_verify /var/lib/rpm/Packages
rpm --rebuilddb

This will delete all the rpm databases and rebuild them.