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Currently the content of this document can copy from the bottom of be a reference to https://ci.apache.org/projects/flink/flink-docs-release-1.11/dev/table/tableApi.html. In future it will be replaced with the syntax of Python Expression DSL.
Built-in Functions
Could be a reference tomoto https://ci.apache.org/projects/flink/flink-docs-release-1.11/dev/table/functions/systemFunctions.html.
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