[gradsusr] Performance hit with data descriptor files?

[Colarco, Peter R. (GSFC-6133)]

Hi-

I am running opengrads 2.0.a7.oga.3/x86_64.

I have a very simple data descriptor file (below) to template a set of large-ish files (gridded 1152 x 721 x 7 points).  When I simply "sdfopen" the first file and plot the first variable/first time/first level, I get my result essentially immediately.  When I instead "xdfopen" the data descriptor file and try to plot the same, it takes some time (~10 sec) to plot.  When I repeat the same sort of thing but operate on several times the difference in performance between the two methods is of course very noticeable.

The issue seems to be in the "options template" line below; taking that out and explicitly putting the first file in I can "xdfopen" the data descriptor file and plot the first variable essentially instantly.  Additional metadata in the data descriptor file (e.g., from make_ctl.sh) does not help or matter as far as I can tell.

Can anyone suggest a solution to this problem?  Am I doing something weird or wrong here?

Data Descriptor File:

dset /path/to/my/data/Y2003/M01/MYD04_L2_ocn.aero_tc8_051.qawt.%y4%m2%d2.nc4
options template
tdef time 248 linear 0z01jan2003 3hr

Thank you,
Pete Colarco



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Peter Colarco
NASA GSFC
Code 613.3
NASA Goddard Space Flight Center
Greenbelt, MD 20771
301.614.6382 (ph)
301.614.5903 (fax)

peter.r.colarco at nasa.gov<mailto:peter.r.colarco at nasa.gov>
http://hyperion.gsfc.nasa.gov/People/Colarco
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