Author: Robert Sample
Subject: Reply to: Reduce CPU Times for Join Sort
Posted: Sat Jun 10, 2017 7:11 pm (GMT 5.5)
Unless you develop a method of getting the results you want without using JOINKEYS, it is unlikely you are going to be able to reduce CPU much -- if any. SORT is already a highly optimized product and hence there is rarely anything an applications programmer can do to reduce its resource usage. Usually the only way to improve performance is to move to a newer machine (assuming your site is not running a z13/z13s already).
Furthermore, 3 minutes of CPU time for 20 million records works out to something like 110,000 records per second of CPU time -- which is pretty good in itself. Why do you think 3 minutes of CPU time is excessive for what you are doing?
_________________
TANSTAAFL
The first rule of code reuse is that the code needs to be worth re-using.
"We should forget about small efficiencies, say about 97% of the time: premature optimization is the root of all evil." -- Donald Knuth
Subject: Reply to: Reduce CPU Times for Join Sort
Posted: Sat Jun 10, 2017 7:11 pm (GMT 5.5)
Unless you develop a method of getting the results you want without using JOINKEYS, it is unlikely you are going to be able to reduce CPU much -- if any. SORT is already a highly optimized product and hence there is rarely anything an applications programmer can do to reduce its resource usage. Usually the only way to improve performance is to move to a newer machine (assuming your site is not running a z13/z13s already).
Furthermore, 3 minutes of CPU time for 20 million records works out to something like 110,000 records per second of CPU time -- which is pretty good in itself. Why do you think 3 minutes of CPU time is excessive for what you are doing?
_________________
TANSTAAFL
The first rule of code reuse is that the code needs to be worth re-using.
"We should forget about small efficiencies, say about 97% of the time: premature optimization is the root of all evil." -- Donald Knuth