[CALCITE-3582] Make RelStructuredTypeFlattener configurable in PlannerImpl

• Type: Task
• Status: Closed
• Priority: Major
• Resolution: Duplicate
• Assignee: Rui Wang
• Reporter: Rui Wang
• Created: 09/Dec/19 23:40
• Updated: 11/Dec/19 20:33
• Resolved: 11/Dec/19 20:33

Description

There is a use case where users want to mix Beam programming model with Beam SQL together to process a dataset. The following is an example of the use case:

dataset.apply(something user defined)
.apply(SELECT row_a, row_b ...)
.apply(something user defined)

As you can see, after the SQL statement is applied, the data structure should be preserved for further processing(e.g. users expect to see there are two rows, than flattened fields of rows)

So far as RelStructuredTypeFlattener is enabled by default in PlannerImpl, Row/Struct will be flattened. But users are very likely defined an output scheme that include row/struct, as that's what they processed in SQL statement.

Make calling RelStructuredTypeFlattener configurable in PlannerImpl to allow disabling it when not needed can be a solution.

Issue Links

• is duplicated by: CALCITE-3138 RelStructuredTypeFlattener doesn't restructure ROW type fields