I’m wondering if it would be possible to add a UNION type in Calcite. My use case is that I am developing a backend storage engine using Calcite that only partially declares its schema. Specifically, the engine declares columns such as ‘int’ when it actually means the column can contain ‘int’ or ‘array of int’. There is no way to tell without actually reading the table if the data is scalar or array. Indeed it can be both.
My idea is that if Calcite had a UNION type, I could declare the columns as e.g. UNION(INT, ARRAY(INT)). Does this sound reasonable? Or is there a better way of handling this situation using the current features of Calcite? Thanks. - A
