We have released some code in a labs release that does compression at the InnoDB IO layer. Let me answer the most frequently asked question. It will work on any OS/File system that supports sparse files and has “punch hole” support. It is not specific to FusionIO. However, I’ve been told by the FusionIO developers that you will get two benefits from FusionIO + NVMFS, no fragmenation issues and more space savings because of a smaller file system block size. Why the block size matters I will attempt to explain next.
The high level idea is rather simple. Given a 16K page we compress it using your favorite compression algorithm and write out the only the compressed data. After writing out the data we “punch a hole” to release the unused part of the original 16K block back to the file system. Let me illustrate with an example:
[DDDDDDDDDDDDDDDD] -> Compress -> [CCCCFFFFFFFFFFFF]
D – Data
F – Free …