copr: Roadmap to chunk-based Enum/Set support in TiKV

[Xuanwo]

Goal

Implement RFC tikv/rfcs#57

Roadmap

• Add Enum/Set type copr: Add mysql Enum and Set support #8849
• Add ChunkedVecEnum/ChunkedVecSet type copr: Implement ChunkedVecEnum #8948 copr: Implement ChunkedVecSet #8988
• Add enum/set into ScalarValue and VectorValue copr: Add enum/set into ScalarValue and VectorValue #9021
• Implement enum/set related copr functions copr: Add enum/set support for codegen #9133
• Implement enum/set related aggr functions
  • Count copr: Add unit test for aggr COUNT #9143
  • First copr: Add test for enum/set support on First aggr #9135
  • Sum copr: Implement ENUM support for aggr SUM #9148 copr: Implement SET support for MAX/MIN/SUM #9184
  • Avg copr: Implement ENUM/SET support for aggr AVG  #9186
  • Max/Min copr: Add ENUM support for aggr MAX #9146 copr: Implement SET support for MAX/MIN/SUM #9184

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• Add elems in FieldType (tipb)
• Export elems from praser to tipb (tidb)
• Extrace elems from FieldType to construct ChunkedVecEnum/ChunkedVecSet

[Xuanwo]

cc @skyzh @breeswish

[skyzh]

Looks good to me!

[skyzh]

Now we have implemented enum and set calculation on TiKV side, and this issue could be closed. The pushdown part is tracked at TiDB repo pingcap/tidb#23619.