[netCDFJava #GCR-931481]: Help regarding slow reading from and writing to netCDF3 files

Hi Daniel,

I'm not aware of any such performance issues in the library –– we read a LOT of 
large files every day and we'd have encountered that problem by now if it 
existed.

For I/O performance in NetCDF, the two dominant factors are number of 
operations and access pattern.

Are you minimizing the number of reads and writes? Try to make big reads and 
cache the data in memory for later use.

Are you reading and writing the data sequentially, or are you jumping around 
within the file, resulting in expensive seek operations? [1] It's important to 
understand how data is laid out in a NetCDF file. But in short, sequential 
access will always be fastest. [2]

Cheers,
Christian

[1] 
http://docs.oracle.com/javase/7/docs/api/java/io/RandomAccessFile.html#seek(long)
[2] 
http://www.unidata.ucar.edu/software/netcdf/docs/file_structure_and_performance.html#netcdf_3_io

Ticket Details
===================
Ticket ID: GCR-931481
Department: Support netCDF Java
Priority: Normal
Status: Closed
===================
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