AVX2 Support

[lmangani]

Great mod and very interesting binding approach! We're also playing with clickhouse-local custom builds towards a slimmer execution engine.

Question: Is there a specific reason for AVX2 to be enabled for Linux systems? This greatly reduces the scope of usage (ie: lambdas, virtualized cpus, etc, fail with Instruction check fail. The CPU does not support AVX2 instruction set.)

Having this disabled (or possibly multiple versions) could broaden compatibility scope enormously. Also the library doesn't seem to be stripped and the distributed .so has 100M+ of trimmable fat.

Thanks!

[auxten]

Thank you for your suggestion. Before, I just thought that most Linux servers should have AVX2 support for performance considerations. Didn't realize usage scenarios like lambdas, virtualized cpus. I'm going to fix this in v0.5.0.

[lmangani]

Thanks! If you would like to support AWS Lambdas and other virtualized system the following patch is also required:

sed -i '/Cannot set thread name/c\' /ClickHouse/src/Common/setThreadName.cpp

Would you accept PRs to the builder?

[auxten]

PR is welcome.

[auxten]

The strip issue is mainly because currently chdb is really new. I need debug info if any crash happens.
The shared lib is built in release mode but with -g flag which means not so much(increased the size by approximately 20%) debug info included.

[lmangani]

That makes sense, although the resulting file is really huge. chdb x86_64 library as installed by pip3

-rwxr-xr-x   1 root staff 527420816 Apr 15 15:37 _chdb.cpython-37m-x86_64-linux-gnu.so*

after strip

-rwxr-xr-x   1 root staff 411978416 Apr 15 15:55 _chdb.cpython-37m-x86_64-linux-gnu.so*

[lmangani]

PR open, moving discussion in thread: #9