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[netCDF #QEA-741463]: NetCDF4 Structural Overhead
- To: Roy.Mendelssohn@xxxxxxxx
- Subject: [netCDF #QEA-741463]: NetCDF4 Structural Overhead
- From: "Unidata netCDF Support" <support-netcdf@xxxxxxxxxxxxxxxx>
- Date: Tue, 08 Apr 2008 21:45:40 -0600
- Delivered-to: support-netcdf@unidata.ucar.edu by laraine.unidata.ucar.edu (Postfix) with ESMTP id 2AF48CB19C; Tue, 8 Apr 2008 21:45:41 -0600 (MDT) id 0CF66D4FBA; Tue, 8 Apr 2008 21:45:40 -0600 (MDT)
Roy,
A little more information on this. According to a presentation given in
November at the HDF/HDF-EOS
workshop, groups have overhead for a B-tree used to manage the objects in each
group. This
overhead is fairly significant. An example given is an HDF5 file with 11,600
groups that used to
require 20 MB in HDF5 version 1.6 but now requires only 12 MB in HDF5 version
1.8. That works out
to about 1000 bytes/group overhead, which may discourage use of lots of small
groups ...
--Russ
Russ Rew UCAR Unidata Program
russ@xxxxxxxxxxxxxxxx http://www.unidata.ucar.edu
Ticket Details
===================
Ticket ID: QEA-741463
Department: Support netCDF
Priority: Normal
Status: Closed