In version 11.0 (Win 8.1 Pro) a query on a large Dataset
for a column that contains Missing
fails most unceremoniously.
With
dsTest = AssociationThread[{"a", "b"},
If[Last@# == 10000, {Missing["No Data"], Last@#}, #]] & /@
Transpose@{RandomChoice[Alphabet[], 22000], Range[22000]} //
Dataset;
One row has column "a"
set to Missing["No Data"]
. Then
dsTest[All, "a"]
Bug, yes?
Work-around
A work-around is to remove the Missing
instances from the Select
.
dsTest[Select[Head[#"a"] =!= Missing &], "a"]
More work-arounds in comments/answers below.
Confirmed Bug - [CASE:3720717]