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Message Posted: Wed, 05 Apr 2006 @ 15:10:30 GMT


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Subj:		Re: TPUMP Blocking on multiple sessions

From:		Vijay R. K.

Hi Bill,

Just let them happen, you can't avoid hash collisions, the fewer AMPs you have the more collisions you will have. Collisions are caused by PI's >being HASHed to the same AMP from both identical and different PI values. With 80 AMPs, and 22000 values, best case, even UPI will have >275 collisions per AMP.

I tried on my system for a table having 119 amps and table having just over a million rows.. The count(distinct(UPI)) and count(distinct(hashrow(UPI))) are giving me exactly the same count.. This seems to indicate that there is no hash collision happening.Am I missing something?

Many thanks

Vijay RK