There is a tradeoff, namely PG returns an error for the expression, however Oracle, MariaDB/MySQL returns NULL for -NULL expression. The behavior depends on what is the exemplar DB is.

PG will deduce the type of null based on other parameters.

we can specify the null type, it will ok.

jackwener=# select -null::int;
 ?column?
----------

(1 row)

deduce the type of null based on other parameters.

jackwener=# select 1+null;
 ?column?
----------

(1 row)

error, can't deduce

jackwener=# select null+null;
ERROR:  operator is not unique: unknown + unknown
LINE 1: select null+null;
                   ^
HINT:  Could not choose a best candidate operator. You might need to add explicit type casts.
jackwener=#

Thank you @drrtuy -- I agree with @jackwener that being more permissive than PG is a good thing.

Benchmark runs are scheduled for baseline = 8022827 and contender = c02e9d4. c02e9d4 is a master commit associated with this PR. Results will be available as each benchmark for each run completes.
Conbench compare runs links:
[Skipped ⚠️ Benchmarking of arrow-datafusion-commits is not supported on ec2-t3-xlarge-us-east-2] ec2-t3-xlarge-us-east-2
[Skipped ⚠️ Benchmarking of arrow-datafusion-commits is not supported on test-mac-arm] test-mac-arm
[Skipped ⚠️ Benchmarking of arrow-datafusion-commits is not supported on ursa-i9-9960x] ursa-i9-9960x
[Skipped ⚠️ Benchmarking of arrow-datafusion-commits is not supported on ursa-thinkcentre-m75q] ursa-thinkcentre-m75q
Buildkite builds:
Supported benchmarks:
ec2-t3-xlarge-us-east-2: Supported benchmark langs: Python, R. Runs only benchmarks with cloud = True
test-mac-arm: Supported benchmark langs: C++, Python, R
ursa-i9-9960x: Supported benchmark langs: Python, R, JavaScript
ursa-thinkcentre-m75q: Supported benchmark langs: C++, Java