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From Robert Coli <>
Subject Re: column sort order and reversed sort performance question
Date Wed, 03 Jul 2013 17:11:08 GMT
On Wed, Jul 3, 2013 at 6:02 AM, Hiller, Dean <> wrote:
> We loaded 5 million columns into a single row and when accessing the
first 30k and last 30k columns we saw no performance difference.  We tried
just loading 2 rows from the beginning and end and saw no performance
difference.  I am sure reverse sort is there for a reason though.  In what
context do you actually see a performance difference with reverse sort???
When a query does not specify a start column (and does not specify
reversed) the server can just start reading columns from the start without
having to worry about finding the right place to start. This is exactly
what we can do for the Descending CF.

For the regular Ascending CF we need to specify reversed, so the server
must read the row index and work out which column is column count from the
end of the row.

There is no comparison really.


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