The database system creates the following B* trees for the LOB values of a table:
One B* tree for the data records (primary tree), sorted by primary key
A common B* tree for all the short LOB values (LOB values < 8 KB)
One additional B* tree for each long LOB value (LOB values > 8 KB)
For the values of the LOB column, the leaf pages of the primary tree contain either links to the common B* tree for the short LOB values or a link to the B* tree of the respective long LOB value.
The following figure shows the B* trees for a table with a LOB column, which contains two short LOB values and two long LOB values.