elastic bool query must match mot getting considered - elasticsearch

Question

i am basically trying to write a query where it should return the document where
school is "holy international" AND grade is "second".
but the issue with the current query is that its not considering the must match query part. ie even though i don't i specify the school is the giving me this document where as it is not a match.
query is giving me all the documents where the grade is second.
i want only document where school is "holy international" AND grade is "second".
as well as i have not specified in the match query for "schools.school" but its giving me results.
mapping
{
"settings": {
"analysis": {
"analyzer": {
"my_keyword_lowercase1": {
"tokenizer": "keyword",
"filter": ["lowercase", "my_pattern_replace1", "trim"]
},
"my_keyword_lowercase2": {
"tokenizer": "standard",
"filter": ["lowercase", "trim"]
}
},
"filter": {
"my_pattern_replace1": {
"type": "pattern_replace",
"pattern": ".",
"replacement": ""
}
}
}
},
"mappings": {
"test_data": {
"properties": {
"schools": {
"type": "nested",
"properties": {
"school": {
"type": "string",
"analyzer": "my_keyword_lowercase1"
},
"grade": {
"type": "string",
"analyzer": "my_keyword_lowercase2"
}
}
}
}
}
}
}
data
{
"_index": "data_index",
"_type": "test_data",
"_id": "57a33ebc1d41",
"_version": 1,
"found": true,
"_source": {
"summary": null,
"schools": [{
"school": "little flower",
"grade": "first",
"date": "2007-06-01",
},
{
"school": "holy international",
"grade": "second",
"date": "2007-06-01",
},
],
"first_name": "Adam",
"location": "Kansas City",
"last_name": "Roger",
"country": "US",
"name": "Adam Roger",
}
}
query
{
"_source": ["first_name"],
"query": {
"nested": {
"path": "schools",
"inner_hits": {
"_source": {
"includes": [
"schools.school",
"schools.grade"
]
}
},
"query": {
"bool": {
"must": {
"match": {
"schools.school": {
"query": "" <-----X didnt specify anything
}
}
},
"filter": {
"match": {
"schools.grade": {
"query": "second",
"operator": "and",
"minimum_should_match": "100%"
}
}
}
}
}
}
}
}
result
{
"took": 26,
"timed_out": false,
"_shards": {
"total": 5,
"successful": 5,
"failed": 0
},
"hits": {
"total": 1,
"max_score": 0.2876821,
"hits": [
{
"_index": "data_test",
"_type": "test_data",
"_id": "57a33ebc1d41",
"_score": 0.2876821,
"_source": {
"first_name": "Adam"
},
"inner_hits": {
"schools": {
"hits": {
"total": 1,
"max_score": 0.2876821,
"hits": [
{
"_nested": {
"field": "schools",
"offset": 0
},
"_score": 0.2876821,
"_source": {
"schools": {
"school": "holy international",
"grade": "second"
}
}
}
]
}
}
}
}
]
}
}

Answer 1

So, basically your problem is analysis step, when I load everything and checked, it become very clear:
This filter completely wipes all string from schools.school field
"filter": {
"my_pattern_replace1": {
"type": "pattern_replace",
"pattern": ".",
"replacement": ""
}
}
I think, that's happening because . is regexp literal, so, when I checked it:
POST /_analyze
{
"field": "schools.school",
"text": "holy international"
}
{
"tokens": [
{
"token": "",
"start_offset": 0,
"end_offset": 18,
"type": "word",
"position": 0
}
]
}
That's why you always get a match, every string you passed during indexing time and during search time becomes "". Some additional info from Elastic wiki - https://www.elastic.co/guide/en/elasticsearch/reference/5.1/analysis-pattern_replace-tokenfilter.html
After I removed patter replace filter, this query returns everything as expected:
{
"_source": ["first_name"],
"query": {
"nested": {
"path": "schools",
"inner_hits": {
"_source": {
"includes": [
"schools.school",
"schools.grade"
]
}
},
"query": {
"bool": {
"must": {
"match": {
"schools.school": {
"query": "holy international"
}
}
},
"filter": {
"match": {
"schools.grade": {
"query": "second"
}
}
}
}
}
}
}
}