Re: [netcdfgroup] slow reads in 4.4.1.1 vs 4.1.3 for some files

Can you do an ncdump with the -s option, so we can see the chunksizes?

On Tue, Dec 13, 2016 at 10:54 AM, Chris Barker <chris.barker@xxxxxxxx>
wrote:

> if I understand the question, this is read times -- is this in fact with
> exactly the same files? In which case the chunking is already set.
>
> less performant decompression??
>
> sounds like the binary search is needed.
>
> Is EVERYTHING else the same? disk system, OS, etc?
>
> -CHB
>
>
> On Tue, Dec 13, 2016 at 9:21 AM, Charlie Zender <zender@xxxxxxx> wrote:
>
>> Hello Simon,
>>
>> Since both files are netCDF4 compressed that
>> means they use chunking. My wild guess is that
>> different chunking defaults cause the observed
>> change in dumping time. You can see the
>> chunk sizes employed with ncdump -s or ncks --hdn,
>> and you can play with the chunk sizes/policy
>> with either.
>>
>> Charlie
>> --
>> Charlie Zender, Earth System Sci. & Computer Sci.
>> University of California, Irvine 949-891-2429 )'(
>>
>>
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>
>
>
> --
>
> Christopher Barker, Ph.D.
> Oceanographer
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