What kind of data structure is an index?
B- trees are the most commonly used data structures for indexes. The reason B- trees
are the most popular data structure for indexes is due to the fact that they are time
efficient – because look-ups, deletions, and insertions can all be done in logarithmic
time. And, another major reason B- trees are more commonly used is because the
data that is stored inside the B- tree can be sorted. The RDBMS typically determines
which data structure is actually used for an index. But, in some scenarios with certain
RDBMS’s, you can actually specify which data structure you want your database to
use when you create the index itself.