Beefy Boxes and Bandwidth Generously Provided by pair Networks
Syntactic Confectionery Delight
 
PerlMonks  

Re^5: Need Speed:Search Tab-delimited File for pairs of names

by Laurent_R (Monsignor)
on Dec 17, 2013 at 10:02 UTC ( #1067443=note: print w/ replies, xml ) Need Help??


in reply to Re^4: Need Speed:Search Tab-delimited File for pairs of names
in thread Need Speed:Search Tab-delimited File for pairs of names

Yes, indeed, a RE search without meta-characters is fast. But index is still faster:

$ perl index_regex_bench.pl Rate Regex Index Regex 5010020/s -- -23% Index 6544503/s 31% --
This is one of the code versions I used, the one with which I obtained the above timings:
#!/usr/bin/perl use Benchmark qw(:all); use strict; use warnings; my $sentence = "The quick brown for jumps over the lazy dog"; my $results = timethese(5000000, { 'Index' => \&code1, 'Regex' => \&code2, }, 'none' ); cmpthese( $results ) ; #------ sub code1 { my $val = index $sentence, "fox" ; } #------ sub code2 { my $val = ($sentence =~ /fox/); }
Using a precompiled regex does not improve the speed of RE search in this case, quite the contrary.


Comment on Re^5: Need Speed:Search Tab-delimited File for pairs of names
Select or Download Code

Log In?
Username:
Password:

What's my password?
Create A New User
Node Status?
node history
Node Type: note [id://1067443]
help
Chatterbox?
and the web crawler heard nothing...

How do I use this? | Other CB clients
Other Users?
Others chilling in the Monastery: (12)
As of 2015-07-29 20:53 GMT
Sections?
Information?
Find Nodes?
Leftovers?
    Voting Booth?

    The top three priorities of my open tasks are (in descending order of likelihood to be worked on) ...









    Results (269 votes), past polls