At 04:32 11/10/2008, you wrote:

>Some of the columns in one of my tables contain mainly nulls, others
>contain very few.
>
>I am trying to improve performance of a procedure which updates many
>rows. The rows have a trigger which compares new/old values and I have
>noticed that the execution speed is much slower when comparing the
>columns with many nulls. eg
>
>Compare new.ColumnWithFewNulls with old.ColumnWithFewNulls = FAST
>
>Compare new.ColumnWithManyNulls with old.ColumnWithManyNulls = SLOW
>
>Is this a known characteristic of nulls?
>If so, is there any way to accelerate this, other than removing the nulls?

What does the test look like (actual code)?

./heLen