source.mode "derived": `statistics` is not supported when `from` is a union of several grids - a relational statistic reduces one grid's own columns, and a union has no single set of them. Derive the statistics of a single grid instead.

Warnings reference › source.derived.union.statistics

Identifier

source.derived.union.statistics

Raised by

The grid (core)

Since

1.52.0

What happened

A relational statistic is computed over one grid's columns, and a union has as many column sets as it has parents. The option does nothing and the union produces its ordinary unioned rows.

The fix

Derive the statistics of a single grid, and union the results if you need several.

Reference

Covered in full at the API reference.