comment on

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
[download]

In reply to Re^3: Processing ~1 Trillion records by clueless newbie
in thread Processing ~1 Trillion records by aossama

Posts are HTML formatted. Put <p> </p> tags around your paragraphs. Put <code> </code> tags around your code and data!

Titles consisting of a single word are discouraged, and in most cases are disallowed outright.

Read Where should I post X? if you're not absolutely sure you're posting in the right place.

Please read these before you post! —

Posts may use any of the Perl Monks Approved HTML tags:

a, abbr, b, big, blockquote, br, caption, center, col, colgroup, dd, del, div, dl, dt, em, font, h1, h2, h3, h4, h5, h6, hr, i, ins, li, ol, p, pre, readmore, small, span, spoiler, strike, strong, sub, sup, table, tbody, td, tfoot, th, thead, tr, tt, u, ul, wbr

You may need to use entities for some characters, as follows. (Exception: Within code tags, you can put the characters literally.)

	For:		Use:
	&		`&`
	<		`<`
	>		`>`
	[		`[`
	]		`]`

Link using PerlMonks shortcuts! What shortcuts can I use for linking?

See Writeup Formatting Tips and other pages linked from there for more info.