Databases Reference
In-Depth Information
Figure 1-10:
Left-deep and bushy trees.
Table 1-2 shows how the number of possible join orders increases as we increase the
number of tables, for both left-deep and bushy trees, and I'll explain how it's calculated
in a moment.
Tables
Left-deep trees
Bushy trees
1
1
1
2
2
2
3
6
12
4
24
120
5
120
1,680
6
720
30,240
7
5,040
665,280
8
40,320
17,297,280
9
362,880
518,918,400
