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In computer science, a B-tree is a self-balancing tree data structure that maintains sorted data and allows searches, sequential access, insertions, and deletions in logarithmic time. The B-tree generalizes the binary search tree, allowing for nodes with more than two children. [2]
A B+ tree consists of a root, internal nodes and leaves. [1] The root may be either a leaf or a node with two or more children. A B+ tree can be viewed as a B-tree in which each node contains only keys (not key–value pairs), and to which an additional level is added at the bottom with linked leaves.
This implementation is a hybrid between the basic bitmap index (without compression) and the list of Row Identifiers (RID-list). Overall, the index is organized as a B+tree. When the column cardinality is low, each leaf node of the B-tree would contain long list of RIDs. In this case, it requires less space to represent the RID-lists as bitmaps.
Pages in category "B-tree" The following 7 pages are in this category, out of 7 total. This list may not reflect recent changes. ...
Rot not only wastes space, but slows query speeds, because a smaller fraction of a rotten index's blocks fit in memory at any one time. In a b-tree, if 14538 gets deleted, its index space remains empty. In a reverse index, if 14538 goes before 24538 arrives, 24538 can reuse 14538's space. [citation needed]
Bagwell [1] presented a time and space efficient solution for tries named Array Mapped Tree (AMT). The Hash array mapped trie (HAMT) is based on AMT. The compact trie node representation uses a bitmap to mark every valid branch – a bitwise trie with bitmap.
A B-tree can be seen as a very specialized form of n-ary tree, one that adds a pile of special restrictions. The restrictions make insertion and deletion a little more complicated -- but, in return, the B-tree can guarantee very fast searches. Some nodes in some n-ary trees have only 1 or 2 children.
He is noted for inventing three data sorting structures: the B-tree (with Edward M. McCreight), the UB-tree (with Volker Markl) and the Red–black tree. Bayer is a recipient of 2001 ACM SIGMOD Edgar F. Codd Innovations Award. In 2005 he was elected as a fellow of the Gesellschaft für Informatik. [2]