Join Example (cont)
Some database statistics:
Sym |
Meaning |
Value |
rS |
# student records |
20,000 |
rE |
# enrollment records |
80,000 |
cS |
Student records/page |
20 |
cE |
Enrolled records/page |
40 |
bS |
# data pages in Student |
1,000 |
bE |
# data pages in Enrolled |
2,000 |
Also, in cost analyses below, N = number of memory buffers.
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