When i run yum update on a server, i get error

[root@server ~]# yum update
error: rpmdb: BDB0113 Thread/process 27693/140218146277184 failed: BDB1507 Thread died in Berkeley DB library
error: db5 error(-30973) from dbenv->failchk: BDB0087 DB_RUNRECOVERY: Fatal error, run database recovery
error: cannot open Packages index using db5 -  (-30973)
error: cannot open Packages database in /var/lib/rpm
CRITICAL:yum.main:

Error: rpmdb open failed
[root@server ~]#

To fix this, you need to delete yum db files (__db.001, __db.002 and __db.003) from /var/lib/rpm folder.

rm /var/lib/rpm/__db.*

Run yum clean and update.

yum clean
yun update -y

Now yum will work.