Status

Current state: Under Discussion

Discussion thread: http://apache-flink-mailing-list-archive.1008284.n3.nabble.com/DISCUSS-FLIP-70-Support-Computed-Column-for-Flink-SQL-td33126.html

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Please keep the discussion on the mailing list rather than commenting on the wiki (wiki discussions get unwieldy fast).

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We would put the TableColumn info of the TableSchema into the CatalogTable properties which would be used to persist. For every column expression, there are three items to persist:

• The column name
• The column data type
• The column expression of SQL-style string that looks like that how user writes them(except if the expression contains a UDF, we should expand it's schema path for a complement reference)

When deserializing, we We use SqlParser to parse the expression strings to SqlNodeinto SqlNode, then converts it to RexNode and apply the projections.

Compatibility, Deprecation, and Migration Plan

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