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Most of the regex strings are constant, a few hundred may contain simple constructs like alternation and character classes: (f?oo|bar|baz|etc)[\w\-]*\.[0-9]{3,}) We only extract the data if it matches. As many have suggested I benchmarked a typical case with the actual data and unless something is wrong the difference is extreme:
my %cases = ( 'one_large' => sub { if($text=~/(stuff?)m0r3(?:[^:]*\.)?($big_strin +g)/i){my $match="$1:$2"}}, 'many_small' => sub { for(@strings){ if($text=~/(stuff?)m0r3(?:[^:]* +\.)?($_)/i){my $match="$1:$2"}}}, ); print '$text = ', length $text, " characters\n", '$big_string = ', length $big_string, " characters\n", '@strings = ', scalar @strings, " items\n\n"; cmpthese( 0, \%cases);
Results:
$text = 4578 characters $big_string = 210724 characters @strings = 10634 items Rate many_small one_large many_small 1.05/s -- -100% one_large 630/s 60089% -- --

In reply to Re^2: pattern matching with large regex by Anonymous Monk
in thread pattern matching with large regex by Anonymous Monk

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