B-tree: split
Pseudocode
B-TREE-SPLIT-CHILD(x, i)
1 z = ALLOCATE-NODE()
2 y = x.ci
3 z.leaf = y.leaf
4 z.n = t - 1
5 for j = 1 to t - 1
6 z.keyj = y.keyj + t
7 if not y.leaf
8 for j = 1 to t
9 z.cj = y.cj + t
10 y.n = t - 1
11 for j = x.n + 1 downto i + 1
12 x.cj + 1 = x.cj
13 x.ci + 1 = z
14 for j = x.n downto i
15 x.keyi = y.keyj
16 x.keyi = y.keyt
17 x.n = x.n + 1
18 DISK-WRITE(y)
19 DISK-WRITE(z)
20 DISK-WRITE(x)