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HBase, mail # user - OT - Hash Code Creation


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Re: OT - Hash Code Creation
Andrey Stepachev 2011-03-16, 22:48
Try hash table with double hashing.
Something like this
http://www.java2s.com/Code/Java/Collections-Data-Structure/Hashtablewithdoublehashing.htm

2011/3/17 Peter Haidinyak <[EMAIL PROTECTED]>

> Hi,
>        This is a little off topic but this group seems pretty swift so I
> thought I would ask. I am aggregating a day's worth of log data which means
> I have a Map of over 24 million elements. What would be a good algorithm to
> use for generating Hash Codes for these elements that cut down on
> collisions? I application starts out reading in a log (144 logs in all) in
> about 20 seconds and by the time I reach the last log it is taking around
> 120 seconds. The extra 100 seconds have to do with Hash Table Collisions.
> I've played around with different Hashing algorithms and cut the original
> time from over 300 seconds to 120 but I know I can do better.
> The key I am using for the Map is an alpha-numeric string that is
> approximately 16 character long with the last 4 or 5 character being the
> most unique.
>
> Any ideas?
>
> Thanks
>
> -Pete
>