Query to get random n items from top 100 items in Elastic Search - elasticsearch

Question

I need to write a query in elasticsearch to get random 12 items in the top 100 sorted items.
I tried something like this, but I am unable to get random 12 items(I can get only the top 12 items).
The query I used:
GET product/_search
{
"sort": [
{
"DateAdded": {
"order": "desc"
}
}
],
"query": {
"function_score": {
"query": {
"bool": {
"must": [
{
"term": {
"definitionName": {
"value": "ABC"
}
}
},
{
"range": {
"price": {
"gt": 0
}
}
}
]
}
},
"functions": [
{
"random_score": {
"seed": 314159265359
}
}
]
}
},
"size": 12
}
Can anybody guide me where am I going wrong? (I am a beginner in writing ElasticQueries)
Thanks in Advance.

Answer 1

EDIT: doesnot work, window_size recalculate score on the X top results.
Also:
need to set: "track_scores" to true at the top level.
corect syntax is:
"rescore": {
"window_size": 10,
"query": {
"score_mode": "max", //wathever
"rescore_query": {
"bool": {
"should": [
{
//your query here - you can use a function or a script score too
}
]
}
},
"query_weight": 0.7,
"rescore_query_weight": 1.2
}
}
Ok i understand better.
Indeed you have to sort by date (top 100) and rescore with a random function (read https://www.elastic.co/guide/en/elasticsearch/reference/7.x/search-request-body.html#request-body-search-post-filter).
Should be something like:
{
"sort": [
{
"DateAdded": {
"order": "desc"
}
}
],
"query": {
"bool": {
"must": [
{
"term": {
"definitionName": {
"value": "ABC"
}
}
},
{
"range": {
"price": {
"gt": 0
}
}
}
]
}
},
"size": 100,
"rescore": {
"window_size": 12,
"query": {
"rescore_query": {
"random_score": {
"seed": 314159265359
}
}
}
}
}