yum 缓存引发的错误

用FC6的添加／删除软件，突然出现如下错误：
Description of problem:

Component: Software Manager
Summary: TB9f78d0ec main.py:244:execute:DatabaseError: database disk image is
malformed

Traceback (most recent call last):
  File "/usr/sbin/pirut", line 390, in ?
    main()
  File "/usr/sbin/pirut", line 386, in main
    pm.run()
  File "/usr/sbin/pirut", line 299, in run
    self.doRefresh()
  File "/usr/sbin/pirut", line 310, in doRefresh
    self.reposSetup(pbar)
  File "/usr/lib/python2.4/site-packages/pirut/__init__.py", line 154, in reposSetup
    self.doSackSetup()
  File "/usr/lib/python2.4/site-packages/yum/__init__.py", line 291, in doSackSetup
    self.repos.populateSack(which=repos)
  File "/usr/lib/python2.4/site-packages/yum/repos.py", line 289, in populateSack
    dobj = repo.cacheHandler.getPrimary(xml, csum)
  File "/usr/lib/python2.4/site-packages/yum/sqlitecache.py", line 96, in getPrimary
    return self._getbase(location, checksum, 'primary')
  File "/usr/lib/python2.4/site-packages/yum/sqlitecache.py", line 89, in _getbase
    self.updateSqliteCache(db, parser, checksum, metadatatype)
  File "/usr/lib/python2.4/site-packages/yum/sqlitecache.py", line 373, in
updateSqliteCache
    cur.execute("DELETE FROM "+table+ " where pkgKey in %s" % delpkgs)
  File "/usr/lib/python2.4/site-packages/sqlite/main.py", line 244, in execute
    self.rs = self.con.db.execute(SQL)
DatabaseError: database disk image is malformed

Local variables in innermost frame:
self:
parms: ()
SQL: DELETE FROM requires where pkgKey in ()


Version-Release number of selected component (if applicable)


通过命令行使用yum提示好多python的错误，重新安装python，还是不行。

原因是：
yum的缓存出错，需要清理一下缓存，使用命令：yum clean dbcache

然后再使用yum
ok了