[CALCITE-5787] Add interface in RelNode for getInputFieldsUsed

[xiedeyantu]

See CALCITE-5787

[xiedeyantu]

Sorry, it's still in draft form and not ready yet. Thank you very much for your comments—I'll carefully consider them.

[xiedeyantu]

I noticed the email Julian sent; it seems we need to discuss this in an email.

Yes, I saw it. I replied in Jira. I think we should continue the discussion in Jira, email was just a temporary measure.

[mihaibudiu]

I am not very sure how this will be used, but this looks fine. You are not covering all existing RelNode types yet.

[xiedeyantu]

I am not very sure how this will be used, but this looks fine. You are not covering all existing RelNode types yet.

This JIRA requirement originates from CALCITE-5740, aiming to more accurately determine which columns from child nodes are actually utilized by parent nodes, thereby facilitating the judgment of whether a conversion to semi-join is possible.

[sonarqubecloud[bot]]

Quality Gate passed

Issues
4 New issues
0 Accepted issues

Measures
0 Security Hotspots
78.5% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarQube Cloud

[xiedeyantu]

The requester of this PR has not provided a clear response, so it may be put on hold for an extended period.

[xiedeyantu]

Hi @julianhyde, since you were the one who proposed this, could you please review this PR when you have time?