search - elasticsearch query issue with ngram -

i have data in index

https://gist.github.com/bitgandtter/6794d9b48ae914a3ac7c

if notice in mapping im using ngram 3 tokens 20.

when execute query:

get /my_index/user/_search?search_type=dfs_query_then_fetch {   "query": {     "filtered": {        "query":{         "multi_match":{           "query": "f",           "fields": ["username","firstname","middlename","lastname"],           "analyzer": "custom_search_analyzer"         }       }     }   } } 

i should 8 documents have indexed 6 leaving out 2 names franz , francis. expect have 2 because f included in data. reason not working.

when execute:

get /my_index/user/_search?search_type=dfs_query_then_fetch {   "query": {     "filtered": {        "query":{         "multi_match":{           "query": "fran",           "fields": ["username","firstname","middlename","lastname"],           "analyzer": "custom_search_analyzer"         }       }     }   } } 

i 2 documents.

if lower ngram start @ 1 documents think affect performance of query.

what im missing here. in advance.

note: examples coded used sense

this expected since min_gram specified 3 mean minimum length of token produced custom analyzer 3 codepoints.

hence first token "franz silva" "fra". hence token "f" not match on document.

one can test out tokens produced analyzer using :

curl -xget "http://<server>/index_name/_analyze?analyzer=custom_analyzer&text=franz silva" 

also note since "custom_analyzer" specified above not specify "token_chars", tokens can contain spaces.