[CALCITE-3550] Make SqlTypeAssignmentRules conversion mapping pluggable

• Type: Improvement
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 1.21.0
• Fix Version/s: 1.22.0
• Component/s: core
• Labels: pull-request-available
• Assignee: Danny Chen
• Reporter: Danny Chen
• Created: 02/Dec/19 09:53
• Updated: 06/Mar/20 04:34
• Resolved: 06/Dec/19 01:10

Description

In CALCITE-2302, we introduce implicit type coercion for Calcite builtin conversion behaviors, we also expand the conversion matrix to support more type conversion compared to the old matrix [1], that means, we implement a conversion matrix of our Calcite style.

As a library of other sql engines, i think we should make the conversion matrix pluggable, so that each engine can customize if the conversion is valid from a type to another.

We have made the TypeCoercion pluggable/customizable, so if this matrix is also pluggable, then, the whole conversion behavior can be customized.

That would give the type conversion of Calcite a pretty good flexibility.

[1] https://docs.google.com/spreadsheets/d/1GhleX5h5W8-kJKh7NMJ4vtoE78pwfaZRJl88ULX_MgU/edit?usp=sharing

Issue Links

• links to: GitHub Pull Request #1629