Investigate and propose Adaptive Join

[SunRunAway]

Feature Request

Is your feature request related to a problem? Please describe:

Sometimes optimizer need defer the choise of Hash Join or Index Nested loops Join because it does not have a deterministic statistics.

Describe the feature you'd like:

We need someone who is familiar with planner and executor to drive and propose a plan, and see how we can be benefited with Adaptive Join.

Describe alternatives you've considered:

Teachability, Documentation, Adoption, Migration Strategy:

• https://docs.microsoft.com/en-us/sql/relational-databases/performance/joins?view=sql-server-ver15#adaptive
• https://docs.oracle.com/database/121/TGSQL/tgsql_optcncpt.htm#GUID-FA5123F0-85A8-47A6-9706-E3FE67B54A50

[Reminiscent]

/assign

[SunRunAway]

@Reminiscent , Thank you.

What we need to do in this issue is,

1. Investigate how can we be benefited from Adaptive Join.
2. If it's really helpful, make a proposal & design docs.

Then let's discuss how we implement in next step.

[qw4990]

@Reminiscent Friendly ping, any update 😆