From: hsv
Date: November 5 2012 6:02pm
Subject: Re: UDF behaves non-deterministic
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>>>> 2012/11/04 22:23 +0000, Stefan Kuhn >>>>
select * from table order by udf(column, 'input_value') desc;
For my understanding, this should give the same result always. 
<<<<<<<<
But if for your data function "udf" returns the same for more arguments there is not enough to fix the order. In that case I have found that other accidental things affect the order, things that one would not suspect: howmuch store is used and needed for the ordering, ... a further reason for showing what the function returns. If the order varies, although the function returns the same in all cases, well, ....