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NOTICE: This version of the NSF Unidata web site (archive.unidata.ucar.edu) is no longer being updated.
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Yes, I get that, but in this case that should only be about an order of magnitude difference in access speed, since he is only reading 8 values (hitting the disk 8 times instead of the 1 time it would take for a variable that is not unlimited.) But he is describing a much larger difference in performance... On Thu, Jun 2, 2016 at 5:01 PM, Dave Allured - NOAA Affiliate < dave.allured@xxxxxxxx> wrote: > On Thu, Jun 2, 2016 at 2:41 PM, Ed Hartnett <edwardjameshartnett@xxxxxxxxx > > wrote: > >> I don't think the fact that it is an unlimited dimension should make it >> any slower, either in classic >> > > <snip> > > Ed, I have experienced this slow down many times with Netcdf-3 classic. > As I said earlier, if the format is classic, then a coordinate variable on > the unlimited dimension is scattered throughout the file. This is > confirmed in the Users' Guide. At the low level, many disk blocks must be > read to get the complete coordinate array. > > --Dave >
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