Beefy Boxes and Bandwidth Generously Provided by pair Networks
"be consistent"
 
PerlMonks  

Uniform distribution of keys in the buckets

by Anonymous Monk
on Mar 29, 2002 at 14:45 UTC ( #155251=note: print w/ replies, xml ) Need Help??


in reply to Re: Re: (Ovid) Re: Comparing two hash tables
in thread Comparing two hash tables

So how can i ensure whether the distribution of keys in the buckets is uniform or not ? Please suggest Thanks


Comment on Uniform distribution of keys in the buckets
Re: Uniform distribution of keys in the buckets
by jmcnamara (Monsignor) on Mar 29, 2002 at 15:21 UTC

    The following will give you some information about the hashing:     print scalar %hash;
    See perldata for information: search for "bucket":

    This is pretty much useful only to find out whether Perl's internal hashing algorithm is performing poorly on your data set. For example, you stick 10,000 things in a hash, but evaluating %HASH in scalar context reveals `"1/16"', which means only one out of sixteen buckets has been touched, and presumably contains all 10,000 of your items. This isn't supposed to happen.

    However, this probably won't help you because you have no control over the hashing mechanism.

    Ultimately, the only way for you to answer your question is to use Benchmark.

    --
    John.

Log In?
Username:
Password:

What's my password?
Create A New User
Node Status?
node history
Node Type: note [id://155251]
help
Chatterbox?
and the web crawler heard nothing...

How do I use this? | Other CB clients
Other Users?
Others browsing the Monastery: (5)
As of 2014-07-26 11:22 GMT
Sections?
Information?
Find Nodes?
Leftovers?
    Voting Booth?

    My favorite superfluous repetitious redundant duplicative phrase is:









    Results (175 votes), past polls