commit ec5934ad8e6aec99f495b094826f69e6df3f6d2b
author Heres, Daniel <danielheres@gmail.com> Thu Mar 04 13:55:57 2021 -0500
committer Andrew Lamb <andrew@nerdnetworks.org> Thu Mar 04 13:55:57 2021 -0500
tree 76dcafeee1195a7ce5b58b3c73fe0c0769124e38
parent 7f62219c7826535edf3b5352954cd006c7516a4e

ARROW-11806: [Rust][DataFusion] Optimize join / inner join creation of indices

This PR implements two optimizations

* Change the way we create an array of indices for an inner join to avoid generating a null bit map. It seems currently not really ergonomic to do this with Arrow without resorting to an iterator (which would be hard to do here). This is around 3% difference
* Allow to reuse allocations in `create_hashes` when possible. This is around 2% faster.

In total this gives a small (5%) speedup to query 5:

This PR:
```
Query 5 iteration 0 took 169.3 ms
Query 5 iteration 1 took 156.0 ms
Query 5 iteration 2 took 157.5 ms
Query 5 iteration 3 took 158.0 ms
Query 5 iteration 4 took 157.3 ms
Query 5 iteration 5 took 163.4 ms
Query 5 iteration 6 took 167.6 ms
Query 5 iteration 7 took 171.5 ms
Query 5 iteration 8 took 167.4 ms
Query 5 iteration 9 took 164.5 ms
Query 5 avg time: 163.26 ms
```

Master:
```
Query 5 iteration 0 took 177.6 ms
Query 5 iteration 1 took 169.6 ms
Query 5 iteration 2 took 171.8 ms
Query 5 iteration 3 took 175.1 ms
Query 5 iteration 4 took 167.2 ms
Query 5 iteration 5 took 171.1 ms
Query 5 iteration 6 took 174.2 ms
Query 5 iteration 7 took 178.1 ms
Query 5 iteration 8 took 167.9 ms
Query 5 iteration 9 took 172.0 ms
Query 5 avg time: 172.46 ms
```

Closes #9595 from Dandandan/opt_hash_join

Authored-by: Heres, Daniel <danielheres@gmail.com>
Signed-off-by: Andrew Lamb <andrew@nerdnetworks.org>