Assignment

To launch, install Docker or Podman and run:

$ cargo test
    Finished `test` profile [unoptimized + debuginfo] target(s) in 0.70s
     Running unittests src/lib.rs (target/debug/deps/supermetal_assignment-a8159c3e18c41f11)

running 1 test
(took 2197.842923 ms)
test test::test_mysql ... ok

test result: ok. 1 passed; 0 failed; 0 ignored; 0 measured; 0 filtered out; finished in 29.89s
...

Future direction

There are a few obvious places to go with this, and you probably don't really care about these, but just so you know I know...:

• Nothing is configurable outside of code. (E.g. the Parquet batch size is a constant.) Might have been better to do a CLI rather than a test. Production code would of course be more configurable/tunable.
• My dataset is a bit lopsided--an employees table with 500K records and a departments table with only 9. This made it a bit difficult to definitively establish how much concurrency actually benefitted in some areas but intuitively it made sense, and would probably bear out on actual data.
• As previously stated, I'm not familiar with Parquet/Arrow outside of my use of it with DuckDB/Overture Maps. There are probably additional ways to speed things up, and I look forward to learning about those when we work together.

Thanks, and do let me know if you have any additional questions.