ESQL: MATCH function failing on locally missing field #136608
Description
Description
A query like FROM ... | WHERE MATCH(first_name, ...) will currently fail to be planned, if first_name is null locally.
The failure is a org.elasticsearch.xpack.esql.VerificationException : "[MATCH] function cannot operate on [first_name], which is not a field from an index mapping".
The reason is the way the planning goes with the locally null fields, replacing all found FieldAttributes with null of the type in ReplaceFieldWithConstantOrNull:
1> [2025-10-15T04:22:54,014][TRACE][o.e.x.e.o.L.changes ][testMatchOnMissingField] Rule local.ReplaceFieldWithConstantOrNull applied with change
1> Limit[1000[INTEGER],false] = Limit[1000[INTEGER],false]
1> \_Filter[MATCH(first_name{f}#4,value[KEYWORD])] ! \_Filter[MATCH(null[KEYWORD],value[KEYWORD])]
1> \_EsRelation[test][_meta_field{f}#9, emp_no{f}#3, first_name{f}#4, gen..] ! \_Project[[_meta_field{f}#9, emp_no{f}#3, first_name{r}#4, gender{f}#5, hire_date{f}#10, job{f}#11, job.raw{f}#12, langu
1> ! ages{f}#6, last_name{f}#7, long_noidx{f}#13, salary{f}#8]]
1> ! \_Eval[[null[KEYWORD] AS first_name#4]]
1> ! \_EsRelation[test][_meta_field{f}#9, emp_no{f}#3, first_name{f}#4, gen..]
A fix could be to adjust the rule, but adjusting the function to allow nulls is probably better.