How to fix rpmdb/yum issues

During my last yum update I ran out of memory and update has been aborted leaving rpmdb in inconsistent state.

When I tried to run it again I've got following error message:
Found 6 pre-existing rpmdb problem(s), 'yum check'
cronie-1.4.4-16.el6_8.2.x86_64 is a duplicate with cronie-1.4.4-15.el6_7.1.x86_64
cronie-anacron-1.4.4-16.el6_8.2.x86_64 is a duplicate with cronie-anacron-1.4.4-15.el6_7.1.x86_64
[..]

Quick fix:
package-cleanup --cleandupes

or:
package-cleanup --dupes
yum-complete-transaction


If you're lucky it should remove old package versions.

package-cleanup can also be executed with --problems flag.

Another cool feature of package-cleanup command is the ability to remove old kernel versions automagically:
package-cleanup --oldkernels