2011 Unidata NetCDF Workshop > The Two NetCDF Data Models
4.14 Classic NetCDF Model Limitations
The classic netCDF data model used for netCDF-3 has some limitations.
Its simplicity makes it is easy to understand, but
limitations include:
- No real data structures, just multidimensional arrays and lists
- No nested structures, variable-length types, or ragged arrays
- Only one shared unlimited dimension for appending
new data
- A flat name space for dimensions and variables
- Character arrays rather than strings
- A small set of numeric types
In addition, the classic netCDF format has performance
limitations for high performance computing with very large
datasets:
- Large variables must be less than 4 GB (per record)
- No real compression supported, just scale/offset packing
- Changing a file schema (the logical structure of the
file) may be very inefficient
- Efficient access sometimes requires data to be read in the same
order as it was written
- Big-endian bias may hamper performance on little-endian
platforms
- I/O is serial in Unidata netCDF-3 (but see Argonne/Northwestern
Parallel netCDF project)
Despite these limitations, netCDF-3 is very widely used in climate
modeling, ocean science, and atmospheric science, and has been used to
represent some very complex data, e.g. grids described in Gridspec specification.
2011 Unidata NetCDF Workshop > The Two NetCDF Data Models