dtrace discuss - May 2010 - Truncating multiple aggregations according to the values in one of them

Hi

I''m using a single printa statement to print multiple aggregations, and
I would like to only show the N lines with the highest value for one of the
printed columns.  E.g:

  printa("%d %@d %@d\n", @totalCost, @totalOccurrences);

and I would like to show the 10 lines with the highest total cost.

Truncating only @totalCost wouldn''t work because when printing multiple
aggregations, a line is printed for each key in the *union* of all presented
aggregations.
Truncating both aggregations wouldn''t work either because
trunc(@totalOccurrences, 10) may remove different keys than trunc(@totalCost,
10) as each truncation is done according to different values.

Any suggestions?
I know I can post-process the output, but would like to check first if there is
an option to take care of this in the DTrace script itself.

Thanks,
Yossi
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This message posted from opensolaris.org

Hey Yossi,

We don''t have a good solution, but there is an RFE filed on this:

  6886670 trunc(@a, @b, @c, @d, @e, ..., 20);

Adam

On May 7, 2010, at 12:32 PM, Yossi Lev wrote:
> Hi
> 
> I''m using a single printa statement to print multiple
aggregations, and I would like to only show the N lines with the highest value
for one of the printed columns.  E.g:
> 
>  printa("%d %@d %@d\n", @totalCost, @totalOccurrences);
> 
> and I would like to show the 10 lines with the highest total cost.
> 
> Truncating only @totalCost wouldn''t work because when printing
multiple aggregations, a line is printed for each key in the *union* of all
presented aggregations.
> Truncating both aggregations wouldn''t work either because
trunc(@totalOccurrences, 10) may remove different keys than trunc(@totalCost,
10) as each truncation is done according to different values.
> 
> Any suggestions?
> I know I can post-process the output, but would like to check first if
there is an option to take care of this in the DTrace script itself.
> 
> Thanks,
> Yossi
> -- 
> This message posted from opensolaris.org
> _______________________________________________
> dtrace-discuss mailing list
> dtrace-discuss at opensolaris.org

--
Adam Leventhal, Fishworks                        http://blogs.sun.com/ahl

Great, thanks Adam.

Yossi
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This message posted from opensolaris.org