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Re^3: Processing ~1 Trillion records

by clueless newbie (Hermit)
on Oct 25, 2012 at 12:51 UTC ( #1000857=note: print w/ replies, xml ) Need Help??


in reply to Re^2: Processing ~1 Trillion records
in thread Processing ~1 Trillion records

To quote Tim Bunce

- while(@row = $sth->fetchrow_array) { } " one column: 51,155 fetches per second " 20 columns: 24,032 fetches per second - while($row = $sth->fetchrow_arrayref) { } " one column: 58,653 fetches per second - approximately 12% faster " 20 columns: 49,390 fetches per second - approximately 51% faster - while($row = shift(@$rowcache) || shift(@{$rowcache=$sth->fetchall_a +rrayref(undef, $max_rows)})) { } " one column: 348,140 fetches per second - by far the fastest! " 20 columns: 42,128 fetches per second - now slower than fetchrow_ +arrayref! " Why? Balance time saved making fewer calls with time spent managi +ng more memory " Do your own benchmarks to find what works best for your situation +s


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