Newbie question: why were AVL trees introduced?

["Jesus Javier Arauz (ML/EEM)" <jesus.javier.arauz@ericsson.com>]

Hi,

I'm porting a prototype I wrote using OpenLDAP 2.0.27 to a newer version (2.1.19) and I've found that in the back-end modules an AVL tree has been introduced in the ldapinfo struct to store Connection instances where there was just a single pointer before. Can anybody please tell me why was this done, or perhaps point me to some document where it is explained?.

Thanks in advance,
/Javier