differences (function? performance?) between 'db2' & 'kldap' as database_module?

[PGNet Dev]

hi,

i've installed openDS ldap server to using krb5/gssapi for authentication.

can anyone point to a reference that compares/contrasts the
differences using 'db2' & 'kldap' as kerberos database modules?

it'c clear both can be used; my question is -- what are the criteria
for choosing one over the other?

thanks.