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A B+ tree is an m-ary tree with a variable but often large number of children per node. 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 of depth n+1 can hold about U times as many items as a B-tree of depth n, but the cost of search, insert, and delete operations grows with the depth of the tree. As with any balanced tree, the cost grows much more slowly than the number of elements.
Database tables and indexes may be stored on disk in one of a number of forms, including ordered/unordered flat files, ISAM, heap files, hash buckets, or B+ trees. Each form has its own particular advantages and disadvantages. The most commonly used forms are B-trees and ISAM.
B-trees are a variant of (a,b) trees, so the (a,b) tree article should contain pretty much everything except stuff like the fact that a = B/4 and b = B/2 in a B-tree. Moved this text to the discussion section from the main definition. Chadloder 18:34 Jan 22, 2003 (UTC) The original author interchanged between B+-tree and B-tree.
Most operations on a binary search tree (BST) take time directly proportional to the height of the tree, so it is desirable to keep the height small. A binary tree with height h can contain at most 2 0 +2 1 +···+2 h = 2 h+1 −1 nodes. It follows that for any tree with n nodes and height h: + And that implies:
To turn a regular search tree into an order statistic tree, the nodes of the tree need to store one additional value, which is the size of the subtree rooted at that node (i.e., the number of nodes below it). All operations that modify the tree must adjust this information to preserve the invariant that size[x] = size[left[x]] + size[right[x]] + 1
I think it's fair to keep SQLite on that list as it is. The term "B+ tree" is only relevant when data records consist of a lookup field (e.g. table's primary key) and non-lookup data fields (rest of table data). In the case of regular database indexes, the whole index record is the lookup key, therefore a B+ tree and B-tree would be equivalent ...
Bounding volume hierarchy, also referred to as bounding volume tree (BV-tree, BVT) Boyer–Moore string-search algorithm; Boyer–Moore–Horspool algorithm; bozo sort; B+ tree; BPP (complexity) Bradford's law; branch (as in control flow) branch (as in revision control) branch and bound; breadth-first search; Bresenham's line algorithm; brick ...