Changes to the B* tree structure can lead to a non-uniform distribution of the data pages. If some branches of the B* tree have more pages than others, data page distribution is not uniform. This can affect system performance, because more accesses are generally required to find data.
Non-uniform distributions are detected by the database system when INSERT, UPDATE, or DELETE statements are performed and the tree is rebalanced when the current operation is carried out. This means that the tree is constantly maintained for optimum operation. During this procedure, page entries are moved to new locations and page pointers are redirected. As a result, data pages are used more efficiently.
Uniform distribution of data prevents individual data areas from overflowing.The only restriction on the size of tables is the storage space available in the database system.