Slideshow:
The B-tree (predecessor of the B+-tree)
Only difference: B-tree does not use the last pointer
So you cannot perform a sequential (ordered) access to the data records using a B-tree
- B-tree:
- B-tree:
- The leaf nodes in
a B-tree
is not linked
I.e.:
- The last record pointer in a leaf node is not used
- The leaf nodes in
a B-tree
is not linked
Graphically:
- B-tree:
- We will only
use B+-trees
because:
- It's very little effort
to maintain the
links in the
leaf nodes
- We need the ability
to
traverse the
records in an
ordered manner
- The links between the leaf nodes allows us to traverse the records in an ordered manner !!!!
- It's very little effort
to maintain the
links in the
leaf nodes
- Therefore:
- Whenever I mentioned:
- B-tree
I really mean:
- B+-tree !!!
(There are a few places in the notes where I forgot to put the super script)
- Whenever I mentioned: