Before compression, the size of chunks is the same. But, I would like to know if after compression chunks are the same size ?
Secondly, I need to understand the issue about space allocation on compression in parallel:
If I have well understood: data are firstly compressed then can be write in parallel on file. But, process don't know where to write chunks in file when they are compressed. The reason is they don't know the new size of chunks compressed.
Is it right what I mean ?
Before compression, the size of chunks is the same. But, I would like to know if after
compression chunks are the same size ?
No, the size of the compressed chunks will generally be different for different
chunks (unless they contain the exact same data). In the worst case, the size
of a compressed chunk could be larger than the original chunk size.
Secondly, I need to understand the issue about space allocation on compression in parallel:
Compression is currently (!) not supported for parallel writes.
However, you can read compressed datasets in parallel.
