ldap_add: Operations error

Hello all,

I am new to open-ldap.
ldapadd -f /usr/local/var/openldap-ldbm/sam.ldif -xv -D "cn=Admin, o=sam" -w secret

i get error as
ldap_add: Operations error

I searched in mailing list in that they asked to delete database.

I did not create database earlier.This is the first time i am runnung this command after installing
openldap-2.0.18. Redhat linux7.1

I have attached slapd.conf and sam.ldif file.

Please porvide me the solution.

One more
Where this database will be created and hoe to delete the database.

Thanks
Suresh