Hi Calcite community, I'm using Calcite to analyze SQL queries and have encountered some issues with transformations that interfere with my use case. I hope the community can provide guidance.
My current workflow: 1. Parse the query into a SqlNode. 2. Validate the SqlNode using SqlValidator (callRewrite=false), applying type coercion and other transformations. 3. Walk the validated SqlNode to perform custom validation, using SqlValidator and SqlValidatorScope for column resolution. 4. Convert the SqlNode to a RelNode. 5. Walk the RelNode for further custom validation. For my use case, I care deeply about the original syntax of the query. I need to preserve the original query structure rather than an equivalent transformation. Steps #2 and #4 introduce changes that create challenges. For example, a comparison between two columns of different types. - <bool_column> = <int_column> is rewritten in step #2 as CAST(<bool_column> AS INT) = <int_column> (AbstractTypeCoercion <https://github.com/apache/calcite/blob/main/core/src/main/java/org/apache/calcite/sql/validate/implicit/AbstractTypeCoercion.java#L157> ). - In step #4, it further transforms into CASE(IS NOT NULL(<bool_column>), CASE(<bool_column>, 1, 0), null) (RexBuilder <https://github.com/apache/calcite/blob/main/core/src/main/java/org/apache/calcite/rex/RexBuilder.java#L940> ). I have two questions: 1. Are the aforementioned types of transformations essential for Calcite to compile queries? Is there a way to disable them while still compiling queries? 2. Is my current approach reasonable, or is there a better way to achieve my goal within Calcite? Any insights would be greatly appreciated. Thanks, Matthew McMillian
