
64 Automated Physical Database Design and Tuning
Tag logical subplan
with index request
Logical subplan
π
c,d
(σ
a=10
(T))
Access Path Generation Module
Available Indexes
Instrumentation Original Optimizer
Physical plans
Project (Filter(...))
FIGURE 4.2 Instrumenting the query optimizer. (Used with permission
from Bruno, N. & Chaudhuri, M. In Proceedings of the ACM of Data [SIG-
MOD], 1993.)
rooted at the operator over which the index request was issued. Specifically,
an index request is an expression of the form N × (T, E, R, P, O, A), where:
• N is the number of times the subplan would be executed. It is greater
than one when the subplan corresponds to the inner ...