pam_mount is a Pluggable Authentication Module that can mount volumes for a user session (login). Supports mounting local filesystems of any kind the normal mount utility supports, with extra code to better support CIFS, FUSE, various crypto, and more.
...This allows to minimize administrative duties, since your users will be able to reuse their existing account to access the database. The plugin requires MySQL 5.5.7 and up. It is compiled as an add on and does not require you to alter MySQL sourcecode, or recompile the entire server. The plugin add support for LDAP using the openLDAP library.
Code for reference implementations of identity brokers and simple single sign-on (SSO) mechanisms that utilize XDI and link contracts to manage the dataweb.