@Gian Merlino @Clint Wylie Wanted to get some clarification on whether ingesting empty strings in both batch/streaming ingests causes the value to be inserted as

NULL

into the segment when

druid.generic.useDefaultValueForNull=true

. Is this the expected behavior? See the data loader photo attached, where it appears to show parsing row 3's

string_value

as an empty string. However, post-segment creation, I took a dump of the segment:

{"__time":1704070860000,"title":"example_1","string_value":"some_value","long_value":1,"double_value":0.1,"float_value":0.2,"multi_value":["a","b","c"],"count":1,"double_value_doubleSum":0.1,"float_value_floatSum":0.2,"long_value_longSum":1}
{"__time":1704070920000,"title":"example_2","string_value":"another_value","long_value":2,"double_value":0.2,"float_value":0.3,"multi_value":["d","e","f"],"count":1,"double_value_doubleSum":0.2,"float_value_floatSum":0.3,"long_value_longSum":2}
{"__time":1704070980000,"title":"example_3","string_value":null,"long_value":0,"double_value":0.0,"float_value":0.0,"multi_value":null,"count":1,"double_value_doubleSum":0.0,"float_value_floatSum":0.0,"long_value_longSum":0}
{"__time":1704071040000,"title":"example_4","string_value":null,"long_value":0,"double_value":0.0,"float_value":0.0,"multi_value":null,"count":1,"double_value_doubleSum":0.0,"float_value_floatSum":0.0,"long_value_longSum":0}

you can see that in row 3, the

string_value

column has replaced what I'd expect to be an

""

with a

null

. This is running on version v31, with

druid.generic.useDefaultValueForNull=true

. I've tested that running on v33 with

druid.generic.useDefaultValueForNull=false

produces the expected result (

""

stored instead of

null

).

With

druid.generic.useDefaultValueForNull=true

, empty strings and nulls both generally got mapped to

null

during ingest