I think you should not have added separate collections/iterables as separate values in the first place... all bets are off on how Solr behaves.
On Fri, Feb 6, 2026 at 6:08 AM Nicolò Rinaldi <[email protected]> wrote: > Hi > > I’m here to ask for some clarification about a behaviour that I encountered > while trying to index matrices with RemoveBlankFieldUpdateProcessorFactory > in > the update processor chain, expecting an error since this syntax isn't > supported in Solr. Here's an example: if I try to index a multivalued field > with values [["cat", "dog"], ["lemon", "orange"]], the field is modified to > ["cat", "dog", "lemon", "orange"]—flattening the 2x2 "matrix" into a 4-item > vector. This flattening seems to happen in the mutate function > < > https://github.com/SeaseLtd/solr/blob/c99af207c761ec34812ef1cc3054eb2804b7448b/solr/core/src/java/org/apache/solr/update/processor/FieldValueMutatingUpdateProcessor.java#L60 > > > of FieldValueMutatingUpdateProcessor. > > This allows the field to be populated even though the syntax is incorrect. > Is there a reason for this behaviour? > > Thanks, > > Nicolò >
