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Re^3: fastest method to use DBI

by targetsmart (Curate)
on Jul 07, 2009 at 05:41 UTC ( #777743=note: print w/ replies, xml ) Need Help??


in reply to Re^2: fastest method to use DBI
in thread fastest method to use DBI

is it the right way to get the fastest fetch?
I don't know, you have run it and give some statistics on the time taken, memory consumption of the perl program, etc.

It would be great help if get an expert comment on the code
I am not a database expert, but IMHO using the database query's OFFSET AND LIMIT is the best way to fetch huge number of records, it is will take only minimum memory(depending on the offset and limit values), and effective values for limit will enable you to fetch all records in a optimum number of fetch cycles.


Vivek
-- 'I' am not the body, 'I' am the 'soul', which has no beginning or no end, no attachment or no aversion, nothing to attain or lose.


Comment on Re^3: fastest method to use DBI
Re^4: fastest method to use DBI
by zwon (Monsignor) on Jul 07, 2009 at 19:19 UTC

    Let me to oppose. OFFSET is not good for performance at all (BTW there's no OFFSET in Oracle AFAIK). When you executing query like

    SELECT name,phone ORDER BY name OFFSET 1000000 LIMIT 10
    your database should iterate over first 1000000 records before it will start returning records, this is very slow.

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