The graphic is divided into two boxes with dotted borders, one on top of the other. The top is labeled "Branch Blocks" and the lower "Leaf Blocks." The graphic contains a tree of boxes. At the top is a box with the following values: 0-40, 41-90, and so on. Three arrows point to a second row of branch blocks. One block in this row has values 1-10, 11-19, 20-25, and so on. An adjacent block has values 41-48, 49-53, and so on. The last black has values 200-209, 210-220, and so on.
The leftmost and rightmost blocks each has a pair of arrows pointing down. The leftmost arrow points to a leaf block containing the following values: 0,rowid, 0,rowid, 10,rowid, and so on. The block to the right contains the following values: 11,rowid, 11,rowid, and so on. The next block contains values: 221,rowid, 222,rowid, and so on. The rightmost block contains the following values: 246,rowid, 248,rowid, and so on. With the exception of the leftmost and rightmost block, each of the leaf blocks in the bottom row is linked by a double-headed arrow to the block on either side.