The PingDirectory Server contains a set of system database index files that ensure that the server operates efficiently. These indexes cannot be modified or deleted.

Index Description
dn2id Allows quick retrieval of DNs. The DN database, or dn2id, has one record for each entry. The key is the normalized entry DN and the value is the entry ID.
id2entry Allows quick retrieval of entries. The id2entry database contains the LDAP entries. The database key is the entry ID and the value is the entry contents.
referral Allows quick retrieval of referrals. The referral database called dn2uri contains URIs from referral entries. The key is the DN of the referral entry and the value is that of a labeled URI in the ref attribute for that entry.
id2children Allows quick retrieval of an entry and its children. The id2children database provides a mapping between an entry's unique identifier and the entry unique identifiers of the corresponding entry's children.
id2subtree Allows quick retrieval of an entry's subtree. The id2subtree database provides a mapping between an entry's unique identifier and its unique identifiers in its subtree.