Repository navigation
transform_values fails when map value column is Dictionary-encoded #25411
Description
transform_values breaks when the map's value field is Dictionary(K, V) encoded
Two problems:
-
Planning: lambda_parameters exposes the raw Dictionary(K, V) type as the lambda variable type, but the lambda body expects the plain value type (Utf8). Type mismatch at planning time.
-
Execution : even if planning passes, flat_values is a Dictionary array and the lambda body receives the wrong type.
should lambda have native support for dictionary instead of introducing a two-way cast?
Metadata
Metadata
Assignees
Labels
No labels
Activity
Rich-T-kid commentedon Sep 17, 2026
cc @LiaCastaneda
LiaCastaneda commentedon Sep 17, 2026
take
LiaCastaneda commentedon Sep 17, 2026
This can happen in any lambda, the error message is basically
internal: LambdaVariable field and schema field mismatch Field { "p0": nullable Utf8 } != Field { "p0": nullable Dictionary(UInt32, Utf8) }fix: cast lambda variables to their declared type instead of erroring (…
fix: cast lambda variables to their declared type instead of erroring (…
fix: cast lambda variables to their declared type instead of erroring (…