When to use hashtable over binary search tree vice verse for Database Index Database Index can be constructed using binary search trees (BST) or HashTables , 

From my understanding so far , HashTables are superior to BST in terms of time taken for searching and insertions however BST beats HashTables hand down in terms of space efficiency  

Under what situation would it be good to use hashtables instead of BST , vice-verse to construct the Database Index , any there any other points i missed out ???.
Use BST where returning ordered records by the indexed column(s) is a typical use case.

Use HT otherwise.