Advantages of B-tree Structure【每日一译】--20121219

The B-tree structure has the following advantages:
■ All leaf blocks of the tree are at the same depth, so retrieval of any record from
anywhere in the index takes approximately the same amount of time.
■ B-tree indexes automatically stay balanced.
■ All blocks of the B-tree are three-quarters full on the average.
■ B-trees provide excellent retrieval performance for a wide range of queries,
including exact match and range searches.
■ Inserts, updates, and deletes are efficient, maintaining key order for fast retrieval.
■ B-tree performance is good for both small and large tables and does not degrade as

the size of a table grows.

B-TREE结构有以下优点:

#所有树的叶块在相同的深度，所以检索任何记录从索引的任何地方花费的时间是近似相同的。

#B-TREE索引自动保持平衡

#所有的B-TREE块平均3/4是满的。

#B-TREE提供了优秀的检索性能对于一个范围查询，包含精确的匹配和范围内的查找。

#插入，更新和删除是有效率的，维护主键顺序有利于快速检索。

#B-TREE性能适合于小表和大表并且随着表数据量的增加而性能是不会下降的。