B-Tree indexs

mysql_High.Performance.MySQL.3rd.Edition.Mar.2012

A B-Tree index speeds up data access because the storage engine doesn’t have to scan

the whole table to find the desired data. Instead, it starts at the root node (not shown

in this figure). The slots in the root node hold pointers to child nodes, and the storage

engine follows these pointers. It finds the right pointer by looking at the values in the

node pages, which define the upper and lower bounds of the values in the child nodes.

Eventually, the storage engine either determines that the desired value doesn’t exist or

successfully reaches a leaf page.