06.03.2025 19:29, Nikhil Kumar Veldanda пишет: > Hi, > >> Overall idea is great. >> >> I just want to mention LZ4 also have API to use dictionary. Its dictionary >> will be as simple as "virtually prepended" text (in contrast to complex >> ZStd dictionary format). >> >> I mean, it would be great if "dictionary" will be common property for >> different algorithms. >> >> On the other hand, zstd have "super fast" mode which is actually a bit >> faster than LZ4 and compresses a bit better. So may be support for >> different algos is not essential. (But then we need a way to change >> compression level to that "super fast" mode.) >> > > zstd compression level and zstd dictionary size is configurable at > attribute level using ALTER TABLE. Default zstd level is 3 and dict > size is 4KB. For super fast mode level can be set to 1.
No. Super-fast mode levels are negative. See parsing "--fast" parameter in `programs/zstdcli.c` in zstd's repository and definition of ZSTD_minCLevel(). So, to support "super-fast" mode you have to accept negative compression levels. I didn't check, probably you're already support them? ------- regards Yura Sokolov aka funny-falcon
