Session – 9 QUERY OPTIMATIZATION. Matakuliah : M0184 / Pengolahan Data Distribusi Tahun : 2005 Versi :. OBJECTIVE. Definition of Query optimization Query Optimization Process Essential aspects of query processing in a distributed environment The importance of query optimization.
Matakuliah : M0184 / Pengolahan Data Distribusi
Tahun : 2005
SEARCH SPACE GENERATION
BEST QEPQuery Optimization Process
Source : Principle of Distributed Database System
There can be very substantial savings in the cost of execution a query or in the length of time the user has to wait for a response.
t : cost for transmitting a tuple
c : overall cost
Cost : (10000 * 1000c) for PATIENT and restricted SURVEY (assume 1000 tuple result)
+ (200 * 1000c) for joining this result and restricted HOSPITALIZATION
Transmit : 200t + 10000t + 1000t
Cost : 1000 * 200c Community Care
+ 100 * 10000c Health Care
Transmit : 200t + 100t + 1000t