# Constant Expression Script Score Returns Two Different Results for Different Queries
**URL:** https://discuss.elastic.co/t/constant-expression-script-score-returns-two-different-results-for-different-queries/189624
**Category:** Elasticsearch
**Created:** [July 9, 2019, 9:03pm UTC](https://discuss.elastic.co/t/constant-expression-script-score-returns-two-different-results-for-different-queries/189624 "2019-07-09T21:03:58Z")
**Posts on this page:** 4
**Page:** 1
### Author:  [@dvisz-inf](https://discuss.elastic.co/u/dvisz-inf)
#### Post date: [July 9, 2019, 9:03pm UTC](https://discuss.elastic.co/t/constant-expression-script-score-returns-two-different-results-for-different-queries/189624/1 "2019-07-09T21:03:58Z")
Hi all 🙂
Using Elasticsearch 6.8.1 I'm seeing some very strange behavior with `script_score`. Using either `expression` or `painless` lang, the script `"42"` which should be a constant expression in either language that evaluates the same value for every document every time, is giving me two different results, even for the same document, when used to score a different query.
```auto
$ cat ~/audit.sh
#!/bin/bash
function search() {
curl -sS -X POST 'http://10.101.0.1:20400/saas/_search?pretty' -H content-type:application/json -d "$1"
}
search '{
"size": 1,
"_source": false,
"query": {
"function_score": {
"script_score": {
"script": {
"lang": "expression",
"source": "42"
}
},
"query": {
"bool": {
"filter": [
{
"exists": {
"field": "social_account.customer_codes"
}
}
]
}
}
}
}
}'
search '{
"size": 1,
"_source": false,
"query": {
"function_score": {
"script_score": {
"script": {
"lang": "expression",
"source": "42"
}
},
"query": {
"term": {
"_id" : "a903c3a5-32f5-45ba-b092-3a80dc4e965a"
}
}
}
}
}'
$ ~/audit.sh
{
"took" : 31,
"timed_out" : false,
"_shards" : {
"total" : 10,
"successful" : 10,
"skipped" : 0,
"failed" : 0
},
"hits" : {
"total" : 441988,
"max_score" : 0.0,
"hits" : [
{
"_index" : "saas-data-2",
"_type" : "_doc",
"_id" : "a903c3a5-32f5-45ba-b092-3a80dc4e965a",
"_score" : 0.0
}
]
}
}
{
"took" : 1,
"timed_out" : false,
"_shards" : {
"total" : 10,
"successful" : 10,
"skipped" : 0,
"failed" : 0
},
"hits" : {
"total" : 1,
"max_score" : 42.0,
"hits" : [
{
"_index" : "saas-data-2",
"_type" : "_doc",
"_id" : "a903c3a5-32f5-45ba-b092-3a80dc4e965a",
"_score" : 42.0
}
]
}
}
```
I'm unsure why the score would be `42.0` in some cases and `0.0` in another, even on the same document.
Thanks in advance
---
### Author:  [@dvisz-inf](https://discuss.elastic.co/u/dvisz-inf)
#### Post date: [July 9, 2019, 10:35pm UTC](https://discuss.elastic.co/t/constant-expression-script-score-returns-two-different-results-for-different-queries/189624/2 "2019-07-09T22:35:30Z")
I've solved the issue.
It turns out that `function_score` has a `boost_mode` parameter that is set by default to `product` and according to the `_explain`, the score contribution for the query`exists` is `0.0` while for the `term` query it is `1.0` because the former is run in a filter context.
```auto
{
"_index" : "saas-data-2",
"_type" : "_doc",
"_id" : "a903c3a5-32f5-45ba-b092-3a80dc4e965a",
"matched" : true,
"explanation" : {
"value" : 0.0,
"description" : "sum of:",
"details" : [
{
"value" : 0.0,
"description" : "function score, product of:",
"details" : [
{
"value" : 0.0,
"description" : "ConstantScore(DocValuesFieldExistsQuery [field=social_account.customer_codes])^0.0",
"details" : []
},
{
"value" : 42.0,
"description" : "min of:",
"details" : [
{
"value" : 42.0,
"description" : "script score function, computed with script:\"Script{type=inline, lang='expression', idOrCode='42', options={}, params={}}\" and parameters: \n{}",
"details" : [
{
"value" : 0.0,
"description" : "_score: ",
"details" : [
{
"value" : 0.0,
"description" : "ConstantScore(DocValuesFieldExistsQuery [field=social_account.customer_codes])^0.0",
"details" : []
}
]
}
]
},
{
"value" : 3.4028235E38,
"description" : "maxBoost",
"details" : []
}
]
}
]
},
{
"value" : 0.0,
"description" : "match on required clause, product of:",
"details" : [
{
"value" : 0.0,
"description" : "# clause",
"details" : []
},
{
"value" : 1.0,
"description" : "DocValuesFieldExistsQuery [field=_primary_term]",
"details" : []
}
]
}
]
}
}
```
versus:
```auto
{
"_index" : "saas-data-2",
"_type" : "_doc",
"_id" : "a903c3a5-32f5-45ba-b092-3a80dc4e965a",
"matched" : true,
"explanation" : {
"value" : 42.0,
"description" : "sum of:",
"details" : [
{
"value" : 42.0,
"description" : "function score, product of:",
"details" : [
{
"value" : 1.0,
"description" : "ConstantScore(_id:[6b dd 37 73 76 b9 fb 7d 9f e7 ee 39 6d af 9b d3 dd be dd af 34 75 ce 1e f7 ae 5a])",
"details" : []
},
{
"value" : 42.0,
"description" : "min of:",
"details" : [
{
"value" : 42.0,
"description" : "script score function, computed with script:\"Script{type=inline, lang='expression', idOrCode='42', options={}, params={}}\" and parameters: \n{}",
"details" : [
{
"value" : 1.0,
"description" : "_score: ",
"details" : [
{
"value" : 1.0,
"description" : "ConstantScore(_id:[6b dd 37 73 76 b9 fb 7d 9f e7 ee 39 6d af 9b d3 dd be dd af 34 75 ce 1e f7 ae 5a])",
"details" : []
}
]
}
]
},
{
"value" : 3.4028235E38,
"description" : "maxBoost",
"details" : []
}
]
}
]
},
{
"value" : 0.0,
"description" : "match on required clause, product of:",
"details" : [
{
"value" : 0.0,
"description" : "# clause",
"details" : []
},
{
"value" : 1.0,
"description" : "DocValuesFieldExistsQuery [field=_primary_term]",
"details" : []
}
]
}
]
}
}
```
---
### Author:  [@dvisz-inf](https://discuss.elastic.co/u/dvisz-inf)
#### Post date: [July 10, 2019, 7:05pm UTC](https://discuss.elastic.co/t/constant-expression-script-score-returns-two-different-results-for-different-queries/189624/3 "2019-07-10T19:05:45Z")
So it turns out that 6.5.3 and 6.8.1 behave differently. The results above are from 6.8.1 but in 6.5.3, both queries score the document the same way.
I believe 6.5.3 has a bug that has been fixed in 6.8.1 that hasn't been backported to 6.5.
Is 6.5 still receiving fixes or no?
Thanks!
---
### Author:  [@system](https://discuss.elastic.co/u/system)
#### Post date: [August 7, 2019, 7:05pm UTC](https://discuss.elastic.co/t/constant-expression-script-score-returns-two-different-results-for-different-queries/189624/4 "2019-08-07T19:05:53Z")
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