sunng87 opened a new issue, #18210: URL: https://github.com/apache/datafusion/issues/18210
### Is your feature request related to a problem or challenge? Hello community, I have been thinking about adding [Postgres style JSON operators](https://www.postgresql.org/docs/18/functions-json.html#FUNCTIONS-JSON) for nested data structures, mostly for `Struct` and `List`. These operators include: - `->`, `->>`, `#>>`: Access data field by index/key - `@>`, `<@`, `?`, `?|`, `?&`: Containment testing - `||`, `-`, `#-`: Data structure manipulation - `@?`, `@@`: Predicate testing ### Describe the solution you'd like Just want to make sure I'm in the right direction. 1. I assume we won't have built-in `json` type in datafusion, so these operators will be implemented directly on `Struct`, `List` and other `json`-like primitives directly, following postgres' semantics of them. I noticed we have VARIANT coming to arrow/datafusion, will we have a new `DataType` for `VARIANT`? If so, it will be good option for input and return type of these operators. 2. At the moment, we don't have support for operators on nested data structure and primitives. If the left input is nested, we will assume the right array is nested too, and perform compare operators recursively: https://github.com/apache/datafusion/blob/main/datafusion/physical-expr/src/expressions/binary.rs#L254 I will need to change this behavior. 3. Some of the operators may create dynamic results if the right input is Array. For example, if the right array of `->` is `["a", "b", "c"]`, it is expected to return 3 different data types in result set which breaks our type system. So for these `>` operators, I'm going to support scalar version only. Some of the kernels are going to be implemented in `arrow-rs` first, and integrate into datafusion. Let me know if these changes will make sense, and align with our previous plan if any. And I will start to send pull requests on both repos. ### Describe alternatives you've considered _No response_ ### Additional context _No response_ -- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. To unsubscribe, e-mail: [email protected] For queries about this service, please contact Infrastructure at: [email protected] --------------------------------------------------------------------- To unsubscribe, e-mail: [email protected] For additional commands, e-mail: [email protected]
