Function Score Query

The FunctionScore allows you to modify the score of documents that are retrieved by a query.

In order to use the FunctionScore query and create needed FunctionScoreFunction import the following:

import zio.elasticsearch.query.FunctionScoreQuery
import zio.elasticsearch.query.FunctionScoreFunction._
import zio.elasticsearch.ElasticQuery._

For creating FunctionScore query you require FunctionScoreFunction or multiple of them. You can create these functions in following way.

You can create DecayFunction with DecayFunctionType.Exp using the expDecayFunction method with origin and scale in the following manner:

val function: DecayFunction[Any] = expDecayFunction("field", origin = "11, 12", scale = "2km")

You can create a type-safe DecayFunction with DecayFunctionType.Exp using the expDecayFunction method with origin and scale in the following manner:

val function: DecayFunction[Document] = expDecayFunction(field = Document.field, origin = "11, 12", scale = "2km")

You can create DecayFunction with DecayFunctionType.Gauss using the gaussDecayFunction method with origin and scale in the following manner:

val function: DecayFunction[Any] = gaussDecayFunction(field = "field", origin = "11, 12", scale = "2km")

You can create a type-safe DecayFunction with DecayFunctionType.Gauss using the gaussDecayFunction method with origin and scale in the following manner:

val function: DecayFunction[Document] = gaussDecayFunction(field = Document.field, origin = "11, 12", scale = "2km")

You can create DecayFunction with DecayFunctionType.Linear using the linearDecayFunction method with origin and scale in the following manner:

val function: DecayFunction[Any] = linearDecayFunction(field = "field", origin = "11, 12", scale = "2km")

You can create a type-safe DecayFunction with DecayFunctionType.Linear using the expDecayFunction method with origin and scale in the following manner:

val function: DecayFunction[Document] = linearDecayFunction(field = Document.field, origin = "11, 12", scale = "2km")

You can create FieldValueFactor using the fieldValueFactor method:

val function: FieldValueFactor[Any] = fieldValueFactor(field = "field")

You can create a type-safe FieldValueFactor using the fieldValueFactor method:

val function: FieldValueFactor[Document] = fieldValueFactor(field = Document.field)

You can create RandomScoreFunction using the randomScoreFunction in three different ways depending on amount of parameters you want to use:

val function: RandomScoreFunction[Any] = randomScoreFunction()

val function: RandomScoreFunction[Any] = randomScoreFunction(seed = 10)

val function: RandomScoreFunction[Any] = randomScoreFunction(seed = 10, field = "field")

You can create a type-safe RandomScoreFunction using the randomScoreFunction method:

val function: RandomScoreFunction = randomScoreFunction(seed = 10, field = Document.field)

You can create ScriptScoreFunction using the scriptScoreFunction method with script in following manner:

val function: ScriptScoreFunction[Any] = scriptScoreFunction(script = Script("params.agg1 > 10"))
val function: ScriptScoreFunction[Any] = scriptScoreFunction(scriptSource = "params.agg1 > 10")

You can create WeightFunction using the weightFunction method(you must provide Any type parameter when using):

val function: WeightFunction[Any] = scriptScoreFunction(weight = 10)

You can use these functions to create FunctionScore query using the functionScore method in the following manner:

val randomScoreFunction: RandomScoreFunction[Any] = randomScoreFunction()
val weightFunction: WeightFunction[Any] = scriptScoreFunction(weight = 10)
val query: FunctionScoreQuery[Any] = functionScore(randomScoreFunction, weightFunction)

You can create a type-safe FunctionScore query using the functionScore, if all functions are created type-safe, in the following manner:

val decayFunction: DecayFunction[Document] = expDecayFunction(field = Document.field, origin = "11, 12", scale = "2km")
val randomScoreFunction: RandomScoreFunction[Document] = randomScoreFunction(seed = 10, field = Document.field)
val weightFunction: WeightFunction[Any] = scriptScoreFunction(weight = 10)
val query: FunctionScoreQuery[Document] = functionScore(decayFunction, randomScoreFunction, weightFunction)

If you want to change the boost, you can use boost method:

import zio.elasticsearch.query.DistanceUnit

val queryWithDistance: FunctionScoreQuery[Document] = functionScore(randomScoreFunction(seed = 10, field = Document.field)).boost(5.0)

If you want to change the boostMode, you can use boostMode method:

import zio.elasticsearch.query.DistanceUnit

val queryWithDistance: FunctionScoreQuery[Document] = functionScore(randomScoreFunction(seed = 10, field = Document.field)).boostMode(FunctionScoreBoostMode.Max)

If you want to change the maxBoost, you can use maxBoost method:

import zio.elasticsearch.query.DistanceUnit

val queryWithDistance: FunctionScoreQuery[Document] = functionScore(randomScoreFunction(seed = 10, field = Document.field)).maxBoost(5.0)

If you want to change the minScore, you can use minScore method:

import zio.elasticsearch.query.DistanceUnit

val queryWithDistance: FunctionScoreQuery[Document] = functionScore(randomScoreFunction(seed = 10, field = Document.field)).minScore(5.0)

If you want to change the query, you can use query method:

import zio.elasticsearch.query.DistanceUnit

val queryWithDistance: FunctionScoreQuery[Document] = functionScore(randomScoreFunction(seed = 10, field = Document.field)).query(matches(Document.field, "value"))

If you want to change the scoreMode, you can use scoreMode method:

import zio.elasticsearch.query.DistanceUnit

val queryWithDistance: FunctionScoreQuery[Document] = functionScore(randomScoreFunction(seed = 10, field = Document.field)).scoreMode(FunctionScoreScoreMode.Max)

If you want to add a one or multiple new FunctionScoreFunction you can use withFunctions method:

import zio.elasticsearch.query.DistanceUnit

val queryWithDistance: FunctionScoreQuery[Document] = functionScore(randomScoreFunction(seed = 10, field = Document.field)).withFunctions(scriptScoreFunction(weight = 10))

You can find more information about FunctionScore query here.