In my index  I have data that resembles
Doc 1
"field_1" : "here I am"
"Display_name" :  null
Doc 2
"field_1":"I am also here"
"Display_name" :  "test"
I am trying to remove the display_name field and value from Doc1.
I would like a query to  remove the fields that are Null from the index. I do not want to have to reindex all the data.   I am currently using elastic 2.2
any help would be much appreciated.