從B 樹、B+ 樹、B* 樹談到R 樹
阿新 • • 發佈：2019-02-19
B樹的定義，從下文中，你將看到，或者是用階，或者是用度，如下段文字所述：
Unfortunately, the literature on B-trees is not uniform in its use of terms relating to B-Trees. (Folk & Zoellick 1992, p. 362) Bayer & McCreight (1972), Comer (1979), and others define the order of B-tree as the minimum number of keys in a non-root node. Folk & Zoellick (1992) points out that terminology is ambiguous because the maximum number of keys is not clear. An order 3 B-tree might hold a maximum of 6 keys or a maximum of 7 keys. (Knuth 1998,TAOCP p. 483) avoids the problem by defining the order to be maximum number of children (which is one more than the maximum number of keys).
Unfortunately, the literature on B-trees is not uniform in its use of terms relating to B-Trees. (Folk & Zoellick 1992, p. 362) Bayer & McCreight (1972), Comer (1979), and others define the order of B-tree as the minimum number of keys in a non-root node. Folk & Zoellick (1992) points out that terminology is ambiguous because the maximum number of keys is not clear. An order 3 B-tree might hold a maximum of 6 keys or a maximum of 7 keys. (Knuth 1998,TAOCP p. 483) avoids the problem by defining the order to be maximum number of children (which is one more than the maximum number of keys).