elasticsearch - Elastic Search Aggregation with scripting giving exception -

query failed [failed execute main query]]; nested: groovyscriptexecutionexception[arrayindexoutofboundsexception[-1]];

i using following aggs query

{   "aggs": {     "hscodes_eval": {       "terms": {         "field": "fscode"         },         "aggs": {                 "top_6_fscodes": {                   "terms": {                     "field": "fscode",                      "script": "doc[\"fscode\"].value[0..6]"                   }                 }               }       }   } } 

i want count of documents matching first 6 characters of field fscode. getting above exception.please help.

try this:

{   "aggs": {     "hscodes_eval": {       "terms": {         "field": "fscode"       },       "aggs": {         "top_6_fscodes": {           "terms": {             "script": "fieldvalue=doc['fscode'].value;if(fieldvalue.length()>=7) fieldvalue[0..6] else ''"           }         }       }     }   } } 

but wouldn't this, meaning using script. scripts slow , if have many documents, can add pretty quickly.

haven't thought this, gut feeling says try, at indexing time, put in sub-field of fscode first 6 characters of initial fscode, maybe using truncate filter. then, @ search time, use terms aggregation not on fscode, on subfield defined.