I think the reason is that for the first query the time is spent
mainly for loading your table in main memory.
Then, the second query has only the overhead of computing the sum over
column V1.
To see this, you can run the query, restart monetdbd, and then run the
query again. You should get similar performance to that of the first
run.
Babis
On Fri, Nov 30, 2012 at 1:29 PM, swapnil joshi
Hi Stefan, If monetdb doesn't maintain any caching then when i am creating test1 database which contain demo table which contain 100 million records.
When first time i am executing "SELECT SUM(V1) FROM DEMO;" monetdb gives me result in (11.4s) when immediate i am trying to execute same query "SELECT SUM(V1) FROM DEMO;" It gives me result in (31.065ms)
How / why this happen?
I have also checked my OS memory cache and I have erased OS Memory cache. Now, I am trying same query "SELECT SUM(V1) FROM DEMO;" now also he take same time in milliseconds approximate(30.723ms)
why he first time take lot of time and every next time he take negligible time.
I hope you will clear my problem related of throughput time.
-- Regards, Swapnil K. Joshi
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