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

• To: Dave Allured - NOAA Affiliate <dave.allured@xxxxxxxx>
• Subject: Re: [netcdfgroup] slow reads in 4.4.1.1 vs 4.1.3 for some files
• From: "Simon (Vsevolod) Ilyushchenko" <simonf@xxxxxxxxxx>
• Date: Wed, 14 Dec 2016 17:42:53 -0800

The issue is present in 4.3.1-rc5, but not in 4.3.1-rc4. The only relevant
release note I see is "When opening a netCDF-4 file, streamline the
iteration over objects in the underlying HDF5 file."

I found a 2M file that shows the same problem - see
https://drive.google.com/file/d/0B_ijCK6xm1R1MW1nU2dsWnNXbE0/view?usp=sharing

3 second ncdump with rc4 vs almost 2 minute ncdump with rc5.

Simon

• Follow-Ups:
  • Re: [netcdfgroup] slow reads in 4.4.1.1 vs 4.1.3 for some files
    • From: Dave Allured - NOAA Affiliate

• References:
  • Re: [netcdfgroup] slow reads in 4.4.1.1 vs 4.1.3 for some files
    • From: Charlie Zender
  • Re: [netcdfgroup] slow reads in 4.4.1.1 vs 4.1.3 for some files
    • From: Chris Barker
  • Re: [netcdfgroup] slow reads in 4.4.1.1 vs 4.1.3 for some files
    • From: Ed Hartnett
  • Re: [netcdfgroup] slow reads in 4.4.1.1 vs 4.1.3 for some files
    • From: Simon (Vsevolod) Ilyushchenko
  • Re: [netcdfgroup] slow reads in 4.4.1.1 vs 4.1.3 for some files
    • From: Dave Allured - NOAA Affiliate