Believe me, your DBA or the person who writes queries doesn't need to know how exactly B-tree index works. Or even "B-tree" term. Just being aware about indexes and knowing when and where to add it would be sufficient.
I agree in principle that not everyone needs his entire algorithms curriculum resident in his head all the time. However, a DBA should understand the characteristics of the type of index he is implementing. B-tree isn't the only game in town.
