Newsgroups: comp.lang.perl
Path: utzoo!utgpu!news-server.csri.toronto.edu!rpi!zaphod.mps.ohio-state.edu!van-bc!ubc-cs!alberta!herald.usask.ca!ccu.umanitoba.ca!rahardj
From: rahardj@ccu.umanitoba.ca (Budi Rahardjo)
Subject: Pattern matching of a large dbm file (slow indexing)
Message-ID: <1991May6.163310.21805@ccu.umanitoba.ca>
Followup-To: comp.lang.perl
Keywords: pattern matching, assoicative array, dbm
Sender: rahardj@ccu.umanitoba.ca (Budi Rahardjo)
Organization: University of Manitoba, Winnipeg, Canada
Distribution: world
Date: Mon, 6 May 91 16:33:10 GMT
Lines: 24

How do I get a fast pattern matching in a large associative array ? 

I have a large associative array (approx. 17000), read from a dbm file.
I'd like to match a pattern with the contents of the array.
Assigning the index/keys to an array takes forever ... , never mind 
doing the matching. 
 
dbmopen(RECORD,"dbtest",0666) || die "Can't open dbm file";
@k = keys(%RECORD);  <====== this takes almost 9 seconds !!      
 
For comparison, doing a grep thru a flatfile (with the same contents)
takes 2 secs.
 
If I do several  "@k = keys(%RECORD);", this is going to be 
a problem. 
 
Is there a way I can iterate over dbm file without stepping thru
the index/keys ? (Basically doing a 'grep' on the contents).
Or maybe read the raw-dbm file (without the index), ie treat it
as a flat file ... 
 
Thanks, 
-- budi