Hello, I have already sent this question to the mysql dev forum, but
no one there unfortunately was not able to answer, I hope for your
help)
tell me please: is there already-ldap authentication plugin for mysql
5.5 ?

PavelVD <pdobryakov (AT) gmail (DOT) com> writes:

You may have a look at openldap, in particular the back-sql and
back-ndb databases. Although thouse backends are by no means a plugin
to mySQL, LDAP provides fine grained access control mechanism.

-Dieter

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