zstd VS zlib-ng

If you want this functionality in zstd itself, check this out: https://github.com/facebook/zstd/pull/2349

Interesting to match with the observations from the practice of using ClickHouse[1][2] for time series:

1. Reordering to SOA helps a lot - this is the whole point of column-oriented databases.

2. Specialized codecs like Gorilla[3], DoubleDelta[4], and FPC[5] lose to simply using ZSTD[6] compression in most cases, both in compression ratio and in performance.

3. Specialized time-series DBMS like InfluxDB or TimescaleDB lose to general-purpose relational OLAP DBMS like ClickHouse [7][8][9].

[1] https://clickhouse.com/blog/optimize-clickhouse-codecs-compr...

[2] https://github.com/ClickHouse/ClickHouse

[3] https://clickhouse.com/docs/en/sql-reference/statements/crea...

[4] https://clickhouse.com/docs/en/sql-reference/statements/crea...

[5] https://clickhouse.com/docs/en/sql-reference/statements/crea...

[6] https://github.com/facebook/zstd/

[7] https://arxiv.org/pdf/2204.09795.pdf "SciTS: A Benchmark for Time-Series Databases in Scientific Experiments and Industrial Internet of Things" (2022)

[8] https://gitlab.com/gitlab-org/incubation-engineering/apm/apm... https://gitlab.com/gitlab-org/incubation-engineering/apm/apm...

[9] https://www.sciencedirect.com/science/article/pii/S187705091...

zstd has a long range mode, which lets it find redundancies a gigabyte away. Try --long and --long=31 for very long range mode.

zstd has delta / patch mode, which creates a file that stores the "patch" to create a new file from an old (reference) file. See https://github.com/facebook/zstd/wiki/Zstandard-as-a-patchin...

See the man page: https://github.com/facebook/zstd/blob/dev/programs/zstd.1.md

So I downloaded the Facebook tool https://github.com/facebook/zstd

2.97.

https://github.com/facebook/zstd/issues/1087#issuecomment-44...

They have a nice table on that page: https://github.com/facebook/zstd#benchmarks

Looking at that table, I think LZ4 is a winner. The compression ratio is not too far, compression speed is slightly faster, decompression speed is significantly faster, the code is much simpler so the compiled binary is smaller, and the project is unrelated to Facebook.

In some cases, zstd can offer up to a 30% reduction in compressed storage as compared to other compression mechanisms. Learn more about zstd here.

It is much faster than miniz_oxide and all other safe-Rust implementations, and consistently beats even Zlib. The performance is roughly on par with zlib-ng - sometimes faster, sometimes slower. It is not (yet) as fast as the original libdeflate in C.

Zlib-ng doesn't contain the same code, but it appears that their equivalent inflate() when used with their inflateGetHeader() implementation was affected by a similar problem: https://github.com/zlib-ng/zlib-ng/pull/1328

Also similarly, most client code will be unaffected because `state->head` will be NULL, because they (most client code) won't have used inflateGetHeader() at all.

I wonder if zlib-ng would make a difference, since it has a lot of optimizations for modern hardware.

https://github.com/zlib-ng/zlib-ng/discussions/871

zlib-ng also has adler32 implementations optimized for various architectures: https://github.com/zlib-ng/zlib-ng

Might be interesting to benchmark their implementation too to see how it compares.

zlib-ng: https://github.com/zlib-ng/zlib-ng/blob/develop/functable.c

(2) There are many packages that rely upon zlib and minizip and switching those underlying dependencies is easier said than done. We can't drop zlib completely and switch: "The idea of zlib-ng is not to replace zlib, but to co-exist as a drop-in replacement with a lower threshold for code change." - https://github.com/zlib-ng/zlib-ng

There are already active zlib forks (e.g. https://github.com/zlib-ng/zlib-ng), the problem is with having people move to them. It takes a lot of effort to move mindshare from the original version to a fork, there's some historical examples of it happening, but not a ton.