diff --git a/settings.gradle b/settings.gradle
index 0ad7ee17..62164786 100644
--- a/settings.gradle
+++ b/settings.gradle
@@ -8,6 +8,7 @@ include 'vitrivr-engine-index'
 include 'vitrivr-engine-query'
 include 'vitrivr-engine-server'
 include 'vitrivr-engine-module-cottontaildb'
+include 'vitrivr-engine-module-jsonl'
 include 'vitrivr-engine-module-pgvector'
 include 'vitrivr-engine-module-features'
 include 'vitrivr-engine-module-m3d'
diff --git a/vitrivr-engine-core/src/main/kotlin/org/vitrivr/engine/core/features/metadata/source/exif/ExifMetadataExtractor.kt b/vitrivr-engine-core/src/main/kotlin/org/vitrivr/engine/core/features/metadata/source/exif/ExifMetadataExtractor.kt
index 71851c5a..19c8f7a2 100644
--- a/vitrivr-engine-core/src/main/kotlin/org/vitrivr/engine/core/features/metadata/source/exif/ExifMetadataExtractor.kt
+++ b/vitrivr-engine-core/src/main/kotlin/org/vitrivr/engine/core/features/metadata/source/exif/ExifMetadataExtractor.kt
@@ -65,6 +65,7 @@ private fun convertType(directory: Directory, tagType: Int, type: Type): Value<*
     Type.Short -> Value.Short(directory.getObject(tagType) as Short)
     Type.String -> Value.String(directory.getString(tagType))
     Type.Text -> Value.String(directory.getString(tagType))
+    Type.UUID -> Value.UUIDValue(UUID.fromString(directory.getString(tagType)))
     is Type.BooleanVector -> throw IllegalArgumentException("Unsupported type: $type")
     is Type.DoubleVector -> throw IllegalArgumentException("Unsupported type: $type")
     is Type.FloatVector -> throw IllegalArgumentException("Unsupported type: $type")
diff --git a/vitrivr-engine-core/src/main/kotlin/org/vitrivr/engine/core/model/descriptor/Attribute.kt b/vitrivr-engine-core/src/main/kotlin/org/vitrivr/engine/core/model/descriptor/Attribute.kt
index df1a6930..051a0b43 100644
--- a/vitrivr-engine-core/src/main/kotlin/org/vitrivr/engine/core/model/descriptor/Attribute.kt
+++ b/vitrivr-engine-core/src/main/kotlin/org/vitrivr/engine/core/model/descriptor/Attribute.kt
@@ -1,5 +1,6 @@
 package org.vitrivr.engine.core.model.descriptor
 
+import kotlinx.serialization.Serializable
 import org.vitrivr.engine.core.model.types.Type
 
 /** The name of an attribute. */
@@ -12,4 +13,5 @@ typealias AttributeName = String
  * @author Ralph Gasser
  * @version 1.0.0
  */
+@Serializable
 data class Attribute(val name: AttributeName, val type: Type, val nullable: Boolean = false)
\ No newline at end of file
diff --git a/vitrivr-engine-core/src/main/kotlin/org/vitrivr/engine/core/model/descriptor/Descriptor.kt b/vitrivr-engine-core/src/main/kotlin/org/vitrivr/engine/core/model/descriptor/Descriptor.kt
index bfbe2939..3a64f459 100644
--- a/vitrivr-engine-core/src/main/kotlin/org/vitrivr/engine/core/model/descriptor/Descriptor.kt
+++ b/vitrivr-engine-core/src/main/kotlin/org/vitrivr/engine/core/model/descriptor/Descriptor.kt
@@ -1,14 +1,16 @@
 package org.vitrivr.engine.core.model.descriptor
 
+import kotlinx.serialization.Serializable
 import org.vitrivr.engine.core.model.Persistable
 import org.vitrivr.engine.core.model.metamodel.Schema
 import org.vitrivr.engine.core.model.retrievable.Retrievable
 import org.vitrivr.engine.core.model.retrievable.RetrievableId
+import org.vitrivr.engine.core.model.serializer.UUIDSerializer
 import org.vitrivr.engine.core.model.types.Value
 import java.util.*
 
 /** A typealias to identify the [UUID] identifying a [Descriptor]. */
-typealias DescriptorId = UUID
+typealias DescriptorId = @Serializable(UUIDSerializer::class) UUID
 
 /**
  * A [Persistable] [Descriptor] that can be used to describe a [Retrievable].
diff --git a/vitrivr-engine-core/src/main/kotlin/org/vitrivr/engine/core/model/descriptor/scalar/FloatDescriptor.kt b/vitrivr-engine-core/src/main/kotlin/org/vitrivr/engine/core/model/descriptor/scalar/FloatDescriptor.kt
index b87fa80c..00efb021 100644
--- a/vitrivr-engine-core/src/main/kotlin/org/vitrivr/engine/core/model/descriptor/scalar/FloatDescriptor.kt
+++ b/vitrivr-engine-core/src/main/kotlin/org/vitrivr/engine/core/model/descriptor/scalar/FloatDescriptor.kt
@@ -1,5 +1,6 @@
 package org.vitrivr.engine.core.model.descriptor.scalar
 
+import kotlinx.serialization.Serializable
 import org.vitrivr.engine.core.model.descriptor.Attribute
 import org.vitrivr.engine.core.model.descriptor.DescriptorId
 import org.vitrivr.engine.core.model.descriptor.scalar.ScalarDescriptor.Companion.VALUE_ATTRIBUTE_NAME
@@ -14,7 +15,6 @@ import org.vitrivr.engine.core.model.types.Value
  * @author Ralph Gasser
  * @version 1.0.0
  */
-
 data class FloatDescriptor(
     override var id: DescriptorId,
     override var retrievableId: RetrievableId?,
diff --git a/vitrivr-engine-core/src/main/kotlin/org/vitrivr/engine/core/model/descriptor/scalar/LongDescriptor.kt b/vitrivr-engine-core/src/main/kotlin/org/vitrivr/engine/core/model/descriptor/scalar/LongDescriptor.kt
index a472150d..6e6fb06d 100644
--- a/vitrivr-engine-core/src/main/kotlin/org/vitrivr/engine/core/model/descriptor/scalar/LongDescriptor.kt
+++ b/vitrivr-engine-core/src/main/kotlin/org/vitrivr/engine/core/model/descriptor/scalar/LongDescriptor.kt
@@ -1,5 +1,6 @@
 package org.vitrivr.engine.core.model.descriptor.scalar
 
+
 import org.vitrivr.engine.core.model.descriptor.Attribute
 import org.vitrivr.engine.core.model.descriptor.DescriptorId
 import org.vitrivr.engine.core.model.descriptor.scalar.ScalarDescriptor.Companion.VALUE_ATTRIBUTE_NAME
@@ -14,7 +15,6 @@ import org.vitrivr.engine.core.model.types.Value
  * @author Ralph Gasser
  * @version 1.0.0
  */
-
 data class LongDescriptor(
     override var id: DescriptorId,
     override var retrievableId: RetrievableId?,
diff --git a/vitrivr-engine-core/src/main/kotlin/org/vitrivr/engine/core/model/descriptor/scalar/ScalarDescriptor.kt b/vitrivr-engine-core/src/main/kotlin/org/vitrivr/engine/core/model/descriptor/scalar/ScalarDescriptor.kt
index 452a369f..508dd38b 100644
--- a/vitrivr-engine-core/src/main/kotlin/org/vitrivr/engine/core/model/descriptor/scalar/ScalarDescriptor.kt
+++ b/vitrivr-engine-core/src/main/kotlin/org/vitrivr/engine/core/model/descriptor/scalar/ScalarDescriptor.kt
@@ -1,5 +1,6 @@
 package org.vitrivr.engine.core.model.descriptor.scalar
 
+import kotlinx.serialization.Serializable
 import org.vitrivr.engine.core.model.descriptor.AttributeName
 import org.vitrivr.engine.core.model.descriptor.Descriptor
 import org.vitrivr.engine.core.model.types.Value
@@ -10,6 +11,7 @@ import org.vitrivr.engine.core.model.types.Value
  * @author Ralph Gasser
  * @version 1.1.0
  */
+@Serializable
 sealed interface ScalarDescriptor<T : Value.ScalarValue<*>> : Descriptor {
 
     companion object {
diff --git a/vitrivr-engine-core/src/main/kotlin/org/vitrivr/engine/core/model/query/basics/ComparisonOperator.kt b/vitrivr-engine-core/src/main/kotlin/org/vitrivr/engine/core/model/query/basics/ComparisonOperator.kt
index ae3a0d37..498062bb 100644
--- a/vitrivr-engine-core/src/main/kotlin/org/vitrivr/engine/core/model/query/basics/ComparisonOperator.kt
+++ b/vitrivr-engine-core/src/main/kotlin/org/vitrivr/engine/core/model/query/basics/ComparisonOperator.kt
@@ -1,32 +1,135 @@
 package org.vitrivr.engine.core.model.query.basics
 
 import org.vitrivr.engine.core.model.query.bool.SimpleBooleanQuery
+import org.vitrivr.engine.core.model.types.Value
+import java.util.*
 
 /**
  * Enumeration of comparison operators used by the [SimpleBooleanQuery].
  *
  * @author Ralph Gasser
  * @author Loris Sauter
- * @version 1.1.0
+ * @author Luca Rossetto
+ * @version 1.2.0
  */
 enum class ComparisonOperator(val value: String) {
-    EQ("=="),
-    NEQ("!="),
-    LE("<"),
-    GR(">"),
-    LEQ("<="),
-    GEQ(">="),
-    LIKE("~=");
-
-    companion object{
+    EQ("==") {
+        override fun <T> compare(v1: Value<T>, v2: Value<*>): Boolean = v1.value == v2.value
+    },
+    NEQ("!=") {
+        override fun <T> compare(v1: Value<T>, v2: Value<*>): Boolean = v1.value != v2.value
+    },
+    LE("<") {
+        override fun <T> compare(v1: Value<T>, v2: Value<*>): Boolean =
+            when (v1) {
+                is Value.String -> v1.value < (v2.value as String)
+                is Value.Boolean -> v1.value < (v2.value as Boolean)
+                is Value.Byte -> v1.value < (v2.value as Byte)
+                is Value.DateTime -> v1.value < (v2.value as Date)
+                is Value.Double -> v1.value < (v2.value as Double)
+                is Value.Float -> v1.value < (v2.value as Float)
+                is Value.Int -> v1.value < (v2.value as Int)
+                is Value.Long -> v1.value < (v2.value as Long)
+                is Value.Short -> v1.value < (v2.value as Short)
+                is Value.Text -> v1.value < (v2.value as String)
+                is Value.UUIDValue -> v1.value < (v2.value as UUID)
+                is Value.BooleanVector,
+                is Value.DoubleVector,
+                is Value.FloatVector,
+                is Value.IntVector,
+                is Value.LongVector -> false
+            }
+
+    },
+    GR(">") {
+        override fun <T> compare(v1: Value<T>, v2: Value<*>): Boolean =
+            when (v1) {
+                is Value.String -> v1.value > (v2.value as String)
+                is Value.Boolean -> v1.value > (v2.value as Boolean)
+                is Value.Byte -> v1.value > (v2.value as Byte)
+                is Value.DateTime -> v1.value > (v2.value as Date)
+                is Value.Double -> v1.value > (v2.value as Double)
+                is Value.Float -> v1.value > (v2.value as Float)
+                is Value.Int -> v1.value > (v2.value as Int)
+                is Value.Long -> v1.value > (v2.value as Long)
+                is Value.Short -> v1.value > (v2.value as Short)
+                is Value.Text -> v1.value > (v2.value as String)
+                is Value.UUIDValue -> v1.value > (v2.value as UUID)
+                is Value.BooleanVector,
+                is Value.DoubleVector,
+                is Value.FloatVector,
+                is Value.IntVector,
+                is Value.LongVector -> false
+            }
+
+    },
+    LEQ("<=") {
+        override fun <T> compare(v1: Value<T>, v2: Value<*>): Boolean =
+            when (v1) {
+                is Value.String -> v1.value <= (v2.value as String)
+                is Value.Boolean -> v1.value <= (v2.value as Boolean)
+                is Value.Byte -> v1.value <= (v2.value as Byte)
+                is Value.DateTime -> v1.value <= (v2.value as Date)
+                is Value.Double -> v1.value <= (v2.value as Double)
+                is Value.Float -> v1.value <= (v2.value as Float)
+                is Value.Int -> v1.value <= (v2.value as Int)
+                is Value.Long -> v1.value <= (v2.value as Long)
+                is Value.Short -> v1.value <= (v2.value as Short)
+                is Value.Text -> v1.value <= (v2.value as String)
+                is Value.UUIDValue -> v1.value <= (v2.value as UUID)
+                is Value.BooleanVector,
+                is Value.DoubleVector,
+                is Value.FloatVector,
+                is Value.IntVector,
+                is Value.LongVector -> false
+            }
+
+    },
+    GEQ(">=") {
+        override fun <T> compare(v1: Value<T>, v2: Value<*>): Boolean =
+            when (v1) {
+                is Value.String -> v1.value >= (v2.value as String)
+                is Value.Boolean -> v1.value >= (v2.value as Boolean)
+                is Value.Byte -> v1.value >= (v2.value as Byte)
+                is Value.DateTime -> v1.value >= (v2.value as Date)
+                is Value.Double -> v1.value >= (v2.value as Double)
+                is Value.Float -> v1.value >= (v2.value as Float)
+                is Value.Int -> v1.value >= (v2.value as Int)
+                is Value.Long -> v1.value >= (v2.value as Long)
+                is Value.Short -> v1.value >= (v2.value as Short)
+                is Value.Text -> v1.value >= (v2.value as String)
+                is Value.UUIDValue -> v1.value <= (v2.value as UUID)
+                is Value.BooleanVector,
+                is Value.DoubleVector,
+                is Value.FloatVector,
+                is Value.IntVector,
+                is Value.LongVector -> false
+            }
+
+    },
+    LIKE("~=") {
+        override fun <T> compare(v1: Value<T>, v2: Value<*>): Boolean =
+            when (v1) {
+                is Value.String,
+                is Value.Text -> {
+                    (v1.value as String).replace("\\", "\\\\").replace("[", "\\[").replace("]", "\\]")
+                        .replace("*", "\\*").replace("%", "*").toRegex().matches(v2.value as String)
+                }
+
+                else -> false
+            }
+
+    };
+
+    companion object {
         /**
          * Resolves a [ComparisonOperator] from the given [String].
          *
          * @param str The [String] which should be one of the [ComparisonOperator]
          * @throws IllegalArgumentException In case the given string is not one of the defined ones.
          */
-        fun fromString(str: String):ComparisonOperator{
-            return when(str.trim()){
+        fun fromString(str: String): ComparisonOperator {
+            return when (str.trim()) {
                 EQ.value -> EQ
                 NEQ.value -> NEQ
                 LE.value -> LE
@@ -38,4 +141,7 @@ enum class ComparisonOperator(val value: String) {
             }
         }
     }
+
+    abstract fun <T> compare(v1: Value<T>, v2: Value<*>): Boolean
+
 }
diff --git a/vitrivr-engine-core/src/main/kotlin/org/vitrivr/engine/core/model/retrievable/Retrievable.kt b/vitrivr-engine-core/src/main/kotlin/org/vitrivr/engine/core/model/retrievable/Retrievable.kt
index c04a2577..86cdc765 100644
--- a/vitrivr-engine-core/src/main/kotlin/org/vitrivr/engine/core/model/retrievable/Retrievable.kt
+++ b/vitrivr-engine-core/src/main/kotlin/org/vitrivr/engine/core/model/retrievable/Retrievable.kt
@@ -1,15 +1,17 @@
 package org.vitrivr.engine.core.model.retrievable
 
+import kotlinx.serialization.Serializable
 import org.vitrivr.engine.core.model.Persistable
 import org.vitrivr.engine.core.model.content.element.ContentElement
 import org.vitrivr.engine.core.model.descriptor.Descriptor
 import org.vitrivr.engine.core.model.relationship.Relationship
 import org.vitrivr.engine.core.model.retrievable.attributes.RetrievableAttribute
+import org.vitrivr.engine.core.model.serializer.UUIDSerializer
 import java.util.*
 import java.util.function.Predicate
 
 /** A typealias to identify the [UUID] identifying a [Retrievable]. */
-typealias RetrievableId = UUID
+typealias RetrievableId = @Serializable(UUIDSerializer::class) UUID
 
 /**
  * A [Persistable] and [Retrievable] unit of information stored by vitrivr.
diff --git a/vitrivr-engine-core/src/main/kotlin/org/vitrivr/engine/core/model/serializer/DateSerializer.kt b/vitrivr-engine-core/src/main/kotlin/org/vitrivr/engine/core/model/serializer/DateSerializer.kt
new file mode 100644
index 00000000..7d78a52a
--- /dev/null
+++ b/vitrivr-engine-core/src/main/kotlin/org/vitrivr/engine/core/model/serializer/DateSerializer.kt
@@ -0,0 +1,14 @@
+package org.vitrivr.engine.core.model.serializer
+
+import kotlinx.serialization.KSerializer
+import kotlinx.serialization.descriptors.PrimitiveKind
+import kotlinx.serialization.descriptors.PrimitiveSerialDescriptor
+import kotlinx.serialization.encoding.Decoder
+import kotlinx.serialization.encoding.Encoder
+import java.util.*
+
+object DateSerializer: KSerializer<Date> {
+    override val descriptor = PrimitiveSerialDescriptor("Date", PrimitiveKind.LONG)
+    override fun serialize(encoder: Encoder, value: Date) = encoder.encodeLong(value.time)
+    override fun deserialize(decoder: Decoder): Date = Date(decoder.decodeLong())
+}
\ No newline at end of file
diff --git a/vitrivr-engine-core/src/main/kotlin/org/vitrivr/engine/core/model/serializer/DateTimeSerializer.kt b/vitrivr-engine-core/src/main/kotlin/org/vitrivr/engine/core/model/serializer/DateTimeSerializer.kt
new file mode 100644
index 00000000..3a923c02
--- /dev/null
+++ b/vitrivr-engine-core/src/main/kotlin/org/vitrivr/engine/core/model/serializer/DateTimeSerializer.kt
@@ -0,0 +1,15 @@
+package org.vitrivr.engine.core.model.serializer
+
+import kotlinx.serialization.KSerializer
+import kotlinx.serialization.descriptors.PrimitiveKind
+import kotlinx.serialization.descriptors.PrimitiveSerialDescriptor
+import kotlinx.serialization.encoding.Decoder
+import kotlinx.serialization.encoding.Encoder
+import org.vitrivr.engine.core.model.types.Value
+import java.util.*
+
+object DateTimeSerializer: KSerializer<Value.DateTime> {
+    override val descriptor = PrimitiveSerialDescriptor("DateTime", PrimitiveKind.LONG)
+    override fun serialize(encoder: Encoder, value: Value.DateTime) = encoder.encodeLong(value.value.time)
+    override fun deserialize(decoder: Decoder): Value.DateTime = Value.DateTime(Date(decoder.decodeLong()))
+}
\ No newline at end of file
diff --git a/vitrivr-engine-core/src/main/kotlin/org/vitrivr/engine/core/model/serializer/UUIDSerializer.kt b/vitrivr-engine-core/src/main/kotlin/org/vitrivr/engine/core/model/serializer/UUIDSerializer.kt
new file mode 100644
index 00000000..8cffbf8c
--- /dev/null
+++ b/vitrivr-engine-core/src/main/kotlin/org/vitrivr/engine/core/model/serializer/UUIDSerializer.kt
@@ -0,0 +1,14 @@
+package org.vitrivr.engine.core.model.serializer
+
+import kotlinx.serialization.KSerializer
+import kotlinx.serialization.descriptors.PrimitiveKind
+import kotlinx.serialization.descriptors.PrimitiveSerialDescriptor
+import kotlinx.serialization.encoding.Decoder
+import kotlinx.serialization.encoding.Encoder
+import java.util.UUID
+
+object UUIDSerializer: KSerializer<UUID> {
+    override val descriptor = PrimitiveSerialDescriptor("UUID", PrimitiveKind.STRING)
+    override fun serialize(encoder: Encoder, value: UUID) = encoder.encodeString(value.toString())
+    override fun deserialize(decoder: Decoder): UUID = UUID.fromString(decoder.decodeString())
+}
\ No newline at end of file
diff --git a/vitrivr-engine-core/src/main/kotlin/org/vitrivr/engine/core/model/types/Type.kt b/vitrivr-engine-core/src/main/kotlin/org/vitrivr/engine/core/model/types/Type.kt
index 8f3928aa..c38410f9 100644
--- a/vitrivr-engine-core/src/main/kotlin/org/vitrivr/engine/core/model/types/Type.kt
+++ b/vitrivr-engine-core/src/main/kotlin/org/vitrivr/engine/core/model/types/Type.kt
@@ -1,5 +1,6 @@
 package org.vitrivr.engine.core.model.types
 
+import kotlinx.serialization.Serializable
 import java.util.*
 
 /**
@@ -9,6 +10,7 @@ import java.util.*
  * @author Loris Sauter
  * @version 2.0.0
  */
+@Serializable
 sealed interface Type {
 
     companion object {
@@ -55,6 +57,7 @@ sealed interface Type {
      *
      * Primarily needed, since simple strings and longer texts are treated differently by certain databases.
      */
+    @Serializable
     data object Text : Type {
         override val dimensions: kotlin.Int = 1
         override fun defaultValue(): Value<*> = Value.String("")
@@ -65,6 +68,7 @@ sealed interface Type {
      *
      * Primarily needed, since simple strings and longer texts are treated differently by certain databases.
      */
+    @Serializable
     data object String : Type {
         override val dimensions: kotlin.Int = 1
         override fun defaultValue(): Value<*> = Value.String("")
@@ -73,6 +77,7 @@ sealed interface Type {
     /**
      * A [Type] that represents a [Boolean] value.
      */
+    @Serializable
     data object Boolean : Type {
         override val dimensions: kotlin.Int = 1
         override fun defaultValue(): Value<*> = Value.Boolean(false)
@@ -81,6 +86,7 @@ sealed interface Type {
     /**
      * A [Type] that represents a [Byte] value.
      */
+    @Serializable
     data object Byte : Type {
         override val dimensions: kotlin.Int = 1
         override fun defaultValue(): Value<*> = Value.Byte(0)
@@ -89,6 +95,7 @@ sealed interface Type {
     /**
      * A [Type] that represents a [Short] value.
      */
+    @Serializable
     data object Short : Type {
         override val dimensions: kotlin.Int = 1
         override fun defaultValue(): Value<*> = Value.Short(0)
@@ -97,6 +104,7 @@ sealed interface Type {
     /**
      * A [Type] that represents a [Int] value.
      */
+    @Serializable
     data object Int : Type {
         override val dimensions: kotlin.Int = 1
         override fun defaultValue(): Value<*> = Value.Int(0)
@@ -105,6 +113,7 @@ sealed interface Type {
     /**
      * A [Type] that represents a [Long] value.
      */
+    @Serializable
     data object Long : Type {
         override val dimensions: kotlin.Int = 1
         override fun defaultValue(): Value<*> = Value.Long(0L)
@@ -113,6 +122,7 @@ sealed interface Type {
     /**
      * A [Type] that represents a [Float] value.
      */
+    @Serializable
     data object Float : Type {
         override val dimensions: kotlin.Int = 1
         override fun defaultValue(): Value<*> = Value.Float(0.0f)
@@ -121,6 +131,7 @@ sealed interface Type {
     /**
      * A [Type] that represents a [Double] value.
      */
+    @Serializable
     data object Double : Type {
         override val dimensions: kotlin.Int = 1
         override fun defaultValue(): Value<*> = Value.Double(0.0)
@@ -129,14 +140,25 @@ sealed interface Type {
     /**
      * A [Type] that represents a [Datetime] value.
      */
+    @Serializable
     data object Datetime : Type {
         override val dimensions: kotlin.Int = 1
         override fun defaultValue(): Value<*> = Value.DateTime(Date())
     }
 
+    /**
+     * A [Type] that represents a [UUID] value.
+     */
+    @Serializable
+    data object UUID : Type {
+        override val dimensions: kotlin.Int = 1
+        override fun defaultValue(): Value<*> = Value.UUIDValue(java.util.UUID(0L, 0L))
+    }
+
     /**
      * A [Type] that represents a [BooleanVector] value.
      */
+    @Serializable
     data class BooleanVector(override val dimensions: kotlin.Int) : Type {
         override fun defaultValue(): Value<*> = Value.BooleanVector(this.dimensions)
     }
@@ -144,6 +166,7 @@ sealed interface Type {
     /**
      * A [Type] that represents a [IntVector] value.
      */
+    @Serializable
     data class IntVector(override val dimensions: kotlin.Int) : Type {
         override fun defaultValue(): Value<*> = Value.IntVector(this.dimensions)
     }
@@ -151,6 +174,7 @@ sealed interface Type {
     /**
      * A [Type] that represents a [LongVector] value.
      */
+    @Serializable
     data class LongVector(override val dimensions: kotlin.Int) : Type {
         override fun defaultValue(): Value<*> = Value.LongVector(this.dimensions)
     }
@@ -158,6 +182,7 @@ sealed interface Type {
     /**
      * A [Type] that represents a [FloatVector] value.
      */
+    @Serializable
     data class FloatVector(override val dimensions: kotlin.Int) : Type {
         override fun defaultValue(): Value<*> = Value.FloatVector(this.dimensions)
     }
@@ -165,6 +190,7 @@ sealed interface Type {
     /**
      * A [Type] that represents a [DoubleVector] value.
      */
+    @Serializable
     data class DoubleVector(override val dimensions: kotlin.Int) : Type {
         override fun defaultValue(): Value<*> = Value.DoubleVector(this.dimensions)
     }
diff --git a/vitrivr-engine-core/src/main/kotlin/org/vitrivr/engine/core/model/types/Value.kt b/vitrivr-engine-core/src/main/kotlin/org/vitrivr/engine/core/model/types/Value.kt
index 5bd1dbbb..65d85950 100644
--- a/vitrivr-engine-core/src/main/kotlin/org/vitrivr/engine/core/model/types/Value.kt
+++ b/vitrivr-engine-core/src/main/kotlin/org/vitrivr/engine/core/model/types/Value.kt
@@ -1,5 +1,7 @@
 package org.vitrivr.engine.core.model.types
 
+import kotlinx.serialization.Serializable
+import org.vitrivr.engine.core.model.serializer.DateTimeSerializer
 import java.util.*
 
 /**
@@ -10,6 +12,7 @@ import java.util.*
  * @author Ralph Gasser
  * @version 1.0.0
  */
+@Serializable()
 sealed interface Value<T> {
 
     companion object {
@@ -34,6 +37,7 @@ sealed interface Value<T> {
             is LongArray -> LongVector(value)
             is IntArray -> IntVector(value)
             is Date -> DateTime(value)
+            is UUID -> UUIDValue(value)
             else -> throw IllegalArgumentException("Unsupported data type.")
         }
     }
@@ -41,38 +45,87 @@ sealed interface Value<T> {
     /** The actual, primitive value. */
     val value: T
 
+    /** Reference to the [Type] of the Value*/
+    val type: Type
+
 
     sealed interface ScalarValue<T>: Value<T>
 
     @JvmInline
-    value class String(override val value: kotlin.String) : ScalarValue<kotlin.String>
+    @Serializable
+    value class String(override val value: kotlin.String) : ScalarValue<kotlin.String> {
+        override val type: Type
+            get() = Type.String
+    }
 
     @JvmInline
-    value class Text(override val value: kotlin.String) : ScalarValue<kotlin.String>
+    @Serializable
+    value class Text(override val value: kotlin.String) : ScalarValue<kotlin.String> {
+        override val type: Type
+            get() = Type.Text
+    }
 
     @JvmInline
-    value class Boolean(override val value: kotlin.Boolean) : ScalarValue<kotlin.Boolean>
+    @Serializable
+    value class Boolean(override val value: kotlin.Boolean) : ScalarValue<kotlin.Boolean> {
+        override val type: Type
+            get() = Type.Boolean
+    }
 
     @JvmInline
-    value class Byte(override val value: kotlin.Byte) : ScalarValue<kotlin.Byte>
+    @Serializable
+    value class Byte(override val value: kotlin.Byte) : ScalarValue<kotlin.Byte> {
+        override val type: Type
+            get() = Type.Byte
+    }
 
     @JvmInline
-    value class Short(override val value: kotlin.Short) : ScalarValue<kotlin.Short>
+    @Serializable
+    value class Short(override val value: kotlin.Short) : ScalarValue<kotlin.Short> {
+        override val type: Type
+            get() = Type.Short
+    }
 
     @JvmInline
-    value class Int(override val value: kotlin.Int) : ScalarValue<kotlin.Int>
+    @Serializable
+    value class Int(override val value: kotlin.Int) : ScalarValue<kotlin.Int> {
+        override val type: Type
+            get() = Type.Int
+    }
 
     @JvmInline
-    value class Long(override val value: kotlin.Long) : ScalarValue<kotlin.Long>
+    @Serializable
+    value class Long(override val value: kotlin.Long) : ScalarValue<kotlin.Long> {
+        override val type: Type
+            get() = Type.Long
+    }
 
     @JvmInline
-    value class Float(override val value: kotlin.Float) : ScalarValue<kotlin.Float>
+    @Serializable
+    value class Float(override val value: kotlin.Float) : ScalarValue<kotlin.Float> {
+        override val type: Type
+            get() = Type.Float
+    }
 
     @JvmInline
-    value class Double(override val value: kotlin.Double) : ScalarValue<kotlin.Double>
+    @Serializable
+    value class Double(override val value: kotlin.Double) : ScalarValue<kotlin.Double> {
+        override val type: Type
+            get() = Type.Double
+    }
 
     @JvmInline
-    value class DateTime(override val value: Date) : ScalarValue<Date>
+    @Serializable(with = DateTimeSerializer::class)
+    value class DateTime(override val value: Date) : ScalarValue<Date> {
+        override val type: Type
+            get() = Type.Datetime
+    }
+
+    @JvmInline
+    value class UUIDValue(override val value: UUID) : ScalarValue<UUID> {
+        override val type: Type
+            get() = Type.UUID
+    }
 
     /**
      * A [Vector] in vitrivr-engine maps primitive data types.
@@ -84,50 +137,71 @@ sealed interface Value<T> {
      * @property value The actual, primitive value.
      * @constructor Creates a new [Vector] with the given [value].
      */
+    @Serializable
     sealed interface Vector<T> : Value<T> {
         val size: kotlin.Int
     }
 
 
     @JvmInline
+    @Serializable
     value class BooleanVector(override val value: BooleanArray) : Vector<BooleanArray> {
         constructor(size: kotlin.Int, init: (kotlin.Int) -> kotlin.Boolean = { false }) : this(BooleanArray(size, init))
 
         override val size: kotlin.Int
             get() = this.value.size
+
+        override val type: Type
+            get() = Type.BooleanVector(size)
     }
 
     @JvmInline
+    @Serializable
     value class IntVector(override val value: IntArray) : Vector<IntArray> {
         constructor(size: kotlin.Int, init: (kotlin.Int) -> kotlin.Int = { 0 }) : this(IntArray(size, init))
 
         override val size: kotlin.Int
             get() = this.value.size
+
+        override val type: Type
+            get() = Type.IntVector(size)
     }
 
 
     @JvmInline
+    @Serializable
     value class LongVector(override val value: LongArray) : Vector<LongArray> {
         constructor(size: kotlin.Int, init: (kotlin.Int) -> kotlin.Long = { 0L }) : this(LongArray(size, init))
 
         override val size: kotlin.Int
             get() = this.value.size
+
+        override val type: Type
+            get() = Type.LongVector(size)
     }
 
 
     @JvmInline
+    @Serializable
     value class FloatVector(override val value: FloatArray) : Vector<FloatArray> {
         constructor(size: kotlin.Int, init: (kotlin.Int) -> kotlin.Float = { 0.0f }) : this(FloatArray(size, init))
 
         override val size: kotlin.Int
             get() = this.value.size
+
+        override val type: Type
+            get() = Type.FloatVector(size)
     }
 
     @JvmInline
+    @Serializable
     value class DoubleVector(override val value: DoubleArray) : Vector<DoubleArray> {
         constructor(size: kotlin.Int, init: (kotlin.Int) -> kotlin.Double = { 0.0 }) : this(DoubleArray(size, init))
 
         override val size: kotlin.Int
             get() = this.value.size
+
+        override val type: Type
+            get() = Type.DoubleVector(size)
     }
 }
diff --git a/vitrivr-engine-core/src/main/kotlin/org/vitrivr/engine/core/util/knn/FixedSizePriorityQueue.kt b/vitrivr-engine-core/src/main/kotlin/org/vitrivr/engine/core/util/knn/FixedSizePriorityQueue.kt
new file mode 100644
index 00000000..ccbd0896
--- /dev/null
+++ b/vitrivr-engine-core/src/main/kotlin/org/vitrivr/engine/core/util/knn/FixedSizePriorityQueue.kt
@@ -0,0 +1,38 @@
+package org.vitrivr.engine.core.util.knn
+
+import java.util.*
+
+/**
+ * Ordered List of fixed size, used for KNN operations
+ */
+
+class FixedSizePriorityQueue<T>(private val maxSize: Int, comparator: Comparator<T>) : TreeSet<T>(comparator) {
+
+    init {
+        require(maxSize > 0) { "Maximum size must be greater than zero." }
+    }
+
+    private val elementsLeft: Int
+        get() = this.maxSize - this.size
+
+    override fun add(element: T): Boolean {
+        if (elementsLeft > 0) {
+            // queue isn't full => add element and decrement elementsLeft
+            val added = super.add(element)
+            return added
+        } else {
+            // there is already 1 or more elements => compare to the least
+            val compared = super.comparator().compare(this.last(), element)
+            if (compared > 0) {
+                // new element is larger than the least in queue => pull the least and add new one to queue
+                pollLast()
+                super.add(element)
+                return true
+            } else {
+                // new element is less than the least in queue => return false
+                return false
+            }
+        }
+    }
+
+}
\ No newline at end of file
diff --git a/vitrivr-engine-index/build.gradle b/vitrivr-engine-index/build.gradle
index afefe7ef..9efc97a4 100644
--- a/vitrivr-engine-index/build.gradle
+++ b/vitrivr-engine-index/build.gradle
@@ -13,6 +13,7 @@ dependencies {
 
     /** ScrImage (used for image resizing). */
     implementation group: 'com.sksamuel.scrimage', name: 'scrimage-core', version: version_scrimage
+
 }
 
 /* Publication of vitrivr engine index to Maven Central. */
diff --git a/vitrivr-engine-module-cottontaildb/src/main/kotlin/org/vitrivr/engine/plugin/cottontaildb/Common.kt b/vitrivr-engine-module-cottontaildb/src/main/kotlin/org/vitrivr/engine/plugin/cottontaildb/Common.kt
index 310ffae0..6f7a87ec 100644
--- a/vitrivr-engine-module-cottontaildb/src/main/kotlin/org/vitrivr/engine/plugin/cottontaildb/Common.kt
+++ b/vitrivr-engine-module-cottontaildb/src/main/kotlin/org/vitrivr/engine/plugin/cottontaildb/Common.kt
@@ -61,6 +61,7 @@ internal fun Type.toCottontailType(): Types<*> = when (this) {
     Type.Float -> Types.Float
     Type.Double -> Types.Double
     Type.Datetime -> Types.Date
+    Type.UUID -> Types.Uuid
     is Type.BooleanVector -> Types.BooleanVector(this.dimensions)
     is Type.DoubleVector -> Types.DoubleVector(this.dimensions)
     is Type.FloatVector -> Types.FloatVector(this.dimensions)
@@ -127,6 +128,7 @@ internal fun Value<*>.toCottontailValue(): PublicValue = when (this) {
     is Value.String -> StringValue(this.value)
     is Value.Text -> StringValue(this.value)
     is Value.DateTime -> DateValue(this.value)
+    is Value.UUIDValue -> UuidValue(this.value)
     is Value.BooleanVector -> BooleanVectorValue(this.value)
     is Value.DoubleVector -> DoubleVectorValue(this.value)
     is Value.FloatVector -> FloatVectorValue(this.value)
diff --git a/vitrivr-engine-module-cottontaildb/src/main/kotlin/org/vitrivr/engine/plugin/cottontaildb/descriptors/struct/StructDescriptorReader.kt b/vitrivr-engine-module-cottontaildb/src/main/kotlin/org/vitrivr/engine/plugin/cottontaildb/descriptors/struct/StructDescriptorReader.kt
index c0df79ec..8a2611a1 100644
--- a/vitrivr-engine-module-cottontaildb/src/main/kotlin/org/vitrivr/engine/plugin/cottontaildb/descriptors/struct/StructDescriptorReader.kt
+++ b/vitrivr-engine-module-cottontaildb/src/main/kotlin/org/vitrivr/engine/plugin/cottontaildb/descriptors/struct/StructDescriptorReader.kt
@@ -74,6 +74,7 @@ class StructDescriptorReader(field: Schema.Field<*, StructDescriptor>, connectio
                 Types.Long -> tuple.asLong(name)?.let { Value.Long(it) }
                 Types.Short -> tuple.asShort(name)?.let { Value.Short(it) }
                 Types.String -> tuple.asString(name)?.let { Value.String(it) }
+                Types.Uuid -> tuple.asUuidValue(name)?.let { Value.UUIDValue(it.value) }
                 is Types.BooleanVector -> tuple.asBooleanVector(name)?.let { Value.BooleanVector(it) }
                 is Types.DoubleVector -> tuple.asDoubleVector(name)?.let { Value.DoubleVector(it) }
                 is Types.FloatVector -> tuple.asFloatVector(name)?.let { Value.FloatVector(it) }
diff --git a/vitrivr-engine-module-jsonl/build.gradle b/vitrivr-engine-module-jsonl/build.gradle
new file mode 100644
index 00000000..ef5e253c
--- /dev/null
+++ b/vitrivr-engine-module-jsonl/build.gradle
@@ -0,0 +1,68 @@
+plugins {
+    id 'org.jetbrains.kotlin.plugin.serialization' version "$version_kotlin"
+    id 'maven-publish'
+    id 'signing'
+}
+
+repositories {
+    mavenCentral()
+}
+
+dependencies {
+    api project(':vitrivr-engine-core')
+
+    /** vitrivr engine Core is required for running tests. */
+    testImplementation(testFixtures(project(':vitrivr-engine-core')))
+}
+
+/* Publication of vitrivr engine query to Maven Central. */
+publishing {
+    publications {
+        mavenJava(MavenPublication) {
+            groupId = 'org.vitrivr'
+            artifactId = 'vitrivr-engine-module-jsonl'
+            version = System.getenv().getOrDefault("MAVEN_PUBLICATION_VERSION", version.toString())
+            from components.java
+            pom {
+                name = 'vitrivr Engine JSONL Connection Plugin'
+                description = 'A module that adds a file-based pseudo database using line-wise JSON.'
+                url = 'https://github.com/vitrivr/vitrivr-engine/'
+                licenses {
+                    license {
+                        name = 'MIT License'
+                    }
+                }
+                developers {
+                    developer {
+                        id = 'ppanopticon'
+                        name = 'Ralph Gasser'
+                        email = 'ralph.gasser@unibas.ch'
+                    }
+                    developer {
+                        id = 'lucaro'
+                        name = 'Luca Rossetto'
+                        email = 'rossetto@ifi.uzh.ch'
+                    }
+                }
+                scm {
+                    connection = 'scm:git:https://github.com/vitrivr/vitrivr-engine.git'
+                    url = 'https://github.com/vitrivr/vitrivr-engine/'
+                }
+            }
+        }
+    }
+    repositories {
+        repositories {
+            maven {
+                def releasesRepoUrl = 'https://oss.sonatype.org/service/local/staging/deploy/maven2/'
+                def snapshotsRepoUrl = 'https://oss.sonatype.org/content/repositories/snapshots/'
+                name = "OSSRH"
+                url = version.endsWith('SNAPSHOT') ? snapshotsRepoUrl : releasesRepoUrl
+                credentials {
+                    username = System.getenv("MAVEN_USERNAME")
+                    password = System.getenv("MAVEN_PASSWORD")
+                }
+            }
+        }
+    }
+}
\ No newline at end of file
diff --git a/vitrivr-engine-module-jsonl/src/main/kotlin/org/vitrivr/engine/database/jsonl/AbstractJsonlProvider.kt b/vitrivr-engine-module-jsonl/src/main/kotlin/org/vitrivr/engine/database/jsonl/AbstractJsonlProvider.kt
new file mode 100644
index 00000000..25d5fad2
--- /dev/null
+++ b/vitrivr-engine-module-jsonl/src/main/kotlin/org/vitrivr/engine/database/jsonl/AbstractJsonlProvider.kt
@@ -0,0 +1,23 @@
+package org.vitrivr.engine.database.jsonl
+
+import org.vitrivr.engine.core.database.Connection
+import org.vitrivr.engine.core.database.descriptor.DescriptorInitializer
+import org.vitrivr.engine.core.database.descriptor.DescriptorProvider
+import org.vitrivr.engine.core.database.descriptor.DescriptorWriter
+import org.vitrivr.engine.core.model.descriptor.Descriptor
+import org.vitrivr.engine.core.model.metamodel.Schema
+
+abstract class AbstractJsonlProvider<D : Descriptor> : DescriptorProvider<D> {
+
+    override fun newInitializer(connection: Connection, field: Schema.Field<*, D>): DescriptorInitializer<D> =
+        JsonlInitializer(
+            field,
+            connection as JsonlConnection
+        )
+
+    override fun newWriter(connection: Connection, field: Schema.Field<*, D>): DescriptorWriter<D> =
+        JsonlWriter(
+            field,
+            connection as JsonlConnection
+        )
+}
\ No newline at end of file
diff --git a/vitrivr-engine-module-jsonl/src/main/kotlin/org/vitrivr/engine/database/jsonl/AbstractJsonlReader.kt b/vitrivr-engine-module-jsonl/src/main/kotlin/org/vitrivr/engine/database/jsonl/AbstractJsonlReader.kt
new file mode 100644
index 00000000..2d7bf6b6
--- /dev/null
+++ b/vitrivr-engine-module-jsonl/src/main/kotlin/org/vitrivr/engine/database/jsonl/AbstractJsonlReader.kt
@@ -0,0 +1,88 @@
+package org.vitrivr.engine.database.jsonl
+
+import kotlinx.serialization.SerializationException
+import kotlinx.serialization.json.Json
+import org.vitrivr.engine.core.database.descriptor.DescriptorReader
+import org.vitrivr.engine.core.model.descriptor.Descriptor
+import org.vitrivr.engine.core.model.descriptor.DescriptorId
+import org.vitrivr.engine.core.model.metamodel.Schema
+import org.vitrivr.engine.core.model.query.Query
+import org.vitrivr.engine.core.model.retrievable.RetrievableId
+import org.vitrivr.engine.core.model.retrievable.Retrieved
+import org.vitrivr.engine.database.jsonl.model.AttributeContainerList
+import org.vitrivr.engine.database.jsonl.retrievable.JsonlRetrievableReader
+import java.io.BufferedReader
+import java.io.FileReader
+import java.io.InputStreamReader
+import kotlin.io.path.inputStream
+
+abstract class AbstractJsonlReader<D : Descriptor>(
+    final override val field: Schema.Field<*, D>,
+    final override val connection: JsonlConnection
+) :
+    DescriptorReader<D> {
+
+    /** Prototype used to create new instances. */
+    protected val prototype = this.field.analyser.prototype(this.field)
+
+    private val path = connection.getPath(field)
+
+    protected abstract fun toDescriptor(list: AttributeContainerList): D
+
+    override fun exists(descriptorId: DescriptorId): Boolean {
+        return getAll().any { it.id == descriptorId }
+    }
+
+    override fun get(descriptorId: DescriptorId): D? {
+        return getAll().firstOrNull { it.id == descriptorId }
+    }
+
+    override fun getAll(descriptorIds: Iterable<DescriptorId>): Sequence<D> {
+        val ids = descriptorIds.toSet()
+        return getAll().filter { ids.contains(it.id) }
+    }
+
+    override fun getAll(): Sequence<D> {
+
+        return BufferedReader(InputStreamReader(path.inputStream())).lineSequence().mapNotNull {
+            try {
+                val list = Json.decodeFromString<AttributeContainerList>(it)
+                return@mapNotNull toDescriptor(list)
+            } catch (se: SerializationException) {
+                LOGGER.error(se) { "Error during deserialization" }
+                null
+            } catch (ie: IllegalArgumentException) {
+                LOGGER.error(ie) { "Error during deserialization" }
+                null
+            }
+        }
+
+    }
+
+    override fun queryAndJoin(query: Query): Sequence<Retrieved> {
+        val results = query(query).toList()
+        val ids = results.mapNotNull { it.retrievableId }
+
+        val retrievables = connection.getRetrievableReader().getAll(ids).associateBy { it.id }
+
+        return results.map { descriptor ->
+            val retrieved = retrievables[descriptor.retrievableId]!!
+            retrieved.addDescriptor(descriptor)
+            retrieved as Retrieved
+        }.asSequence()
+    }
+
+    override fun getForRetrievable(retrievableId: RetrievableId): Sequence<D> {
+        return getAll().filter { it.retrievableId == retrievableId}
+    }
+
+    override fun getAllForRetrievable(retrievableIds: Iterable<RetrievableId>): Sequence<D> {
+        val ids = retrievableIds.toSet()
+        return getAll().filter { ids.contains(it.retrievableId) }
+    }
+
+
+    override fun count(): Long {
+        return BufferedReader(InputStreamReader(path.inputStream())).lineSequence().count().toLong()
+    }
+}
\ No newline at end of file
diff --git a/vitrivr-engine-module-jsonl/src/main/kotlin/org/vitrivr/engine/database/jsonl/JsonlConnection.kt b/vitrivr-engine-module-jsonl/src/main/kotlin/org/vitrivr/engine/database/jsonl/JsonlConnection.kt
new file mode 100644
index 00000000..8cf018bd
--- /dev/null
+++ b/vitrivr-engine-module-jsonl/src/main/kotlin/org/vitrivr/engine/database/jsonl/JsonlConnection.kt
@@ -0,0 +1,57 @@
+package org.vitrivr.engine.database.jsonl
+
+import io.github.oshai.kotlinlogging.KotlinLogging.logger
+import org.vitrivr.engine.core.database.AbstractConnection
+import org.vitrivr.engine.core.database.retrievable.RetrievableInitializer
+import org.vitrivr.engine.core.database.retrievable.RetrievableReader
+import org.vitrivr.engine.core.database.retrievable.RetrievableWriter
+import org.vitrivr.engine.core.model.metamodel.Schema
+import org.vitrivr.engine.database.jsonl.retrievable.JsonlRetrievableInitializer
+import org.vitrivr.engine.database.jsonl.retrievable.JsonlRetrievableReader
+import org.vitrivr.engine.database.jsonl.retrievable.JsonlRetrievableWriter
+import java.nio.file.Path
+import kotlin.io.path.absolutePathString
+
+internal val LOGGER = logger("org.vitrivr.engine.database.jsonl.JsonlConnection")
+
+class JsonlConnection(
+    override val schemaName: String,
+    connectionProvider: JsonlConnectionProvider,
+    private val root: Path
+) : AbstractConnection(schemaName, connectionProvider) {
+
+    override fun <T> withTransaction(action: (Unit) -> T): T {
+        LOGGER.warn { "Transactions are not supported by the JsonlConnection" }
+        return action(Unit)
+    }
+
+    internal val schemaRoot = root.resolve(schemaName)
+
+    fun getPath(field: Schema.Field<*, *>) = schemaRoot.resolve("${field.fieldName}.jsonl")
+
+    override fun getRetrievableInitializer(): RetrievableInitializer = JsonlRetrievableInitializer(this)
+
+    private val writer: JsonlRetrievableWriter by lazy { JsonlRetrievableWriter(this) }
+
+    override fun getRetrievableWriter(): RetrievableWriter = writer
+
+    private val reader: JsonlRetrievableReader by lazy { JsonlRetrievableReader(this) }
+
+    override fun getRetrievableReader(): RetrievableReader = reader
+
+    override fun description(): String = "JsonlConnection on '${root.absolutePathString()}'"
+
+    override fun close() {
+        writer.close()
+    }
+
+    companion object {
+
+        /** The column name of a retrievable ID. */
+        const val RETRIEVABLE_ID_COLUMN_NAME = "retrievableId"
+
+        /** The column name of a descriptor ID. */
+        const val DESCRIPTOR_ID_COLUMN_NAME = "descriptorId"
+    }
+
+}
\ No newline at end of file
diff --git a/vitrivr-engine-module-jsonl/src/main/kotlin/org/vitrivr/engine/database/jsonl/JsonlConnectionProvider.kt b/vitrivr-engine-module-jsonl/src/main/kotlin/org/vitrivr/engine/database/jsonl/JsonlConnectionProvider.kt
new file mode 100644
index 00000000..c6fbca90
--- /dev/null
+++ b/vitrivr-engine-module-jsonl/src/main/kotlin/org/vitrivr/engine/database/jsonl/JsonlConnectionProvider.kt
@@ -0,0 +1,59 @@
+package org.vitrivr.engine.database.jsonl
+
+import org.vitrivr.engine.core.database.AbstractConnectionProvider
+import org.vitrivr.engine.core.database.Connection
+import org.vitrivr.engine.core.model.descriptor.scalar.*
+import org.vitrivr.engine.core.model.descriptor.struct.LabelDescriptor
+import org.vitrivr.engine.core.model.descriptor.struct.MapStructDescriptor
+import org.vitrivr.engine.core.model.descriptor.struct.metadata.MediaDimensionsDescriptor
+import org.vitrivr.engine.core.model.descriptor.struct.metadata.Rectangle2DMetadataDescriptor
+import org.vitrivr.engine.core.model.descriptor.struct.metadata.TemporalMetadataDescriptor
+import org.vitrivr.engine.core.model.descriptor.struct.metadata.source.FileSourceMetadataDescriptor
+import org.vitrivr.engine.core.model.descriptor.struct.metadata.source.VideoSourceMetadataDescriptor
+import org.vitrivr.engine.core.model.descriptor.vector.*
+import org.vitrivr.engine.database.jsonl.scalar.ScalarJsonlProvider
+import org.vitrivr.engine.database.jsonl.struct.StructJsonlProvider
+import org.vitrivr.engine.database.jsonl.vector.VectorJsonlProvider
+import java.nio.file.Path
+
+
+class JsonlConnectionProvider() : AbstractConnectionProvider() {
+
+    override val databaseName = "JSONL File Connection"
+    override val version = "1.0.0"
+
+    override fun openConnection(schemaName: String, parameters: Map<String, String>): Connection {
+
+        val rootPath = parameters["root"] ?: "."
+
+        return JsonlConnection(schemaName, this, Path.of(rootPath))
+
+    }
+
+    override fun initialize() {
+        /* Scalar descriptors. */
+        this.register(BooleanDescriptor::class, ScalarJsonlProvider)
+        this.register(IntDescriptor::class, ScalarJsonlProvider)
+        this.register(LongDescriptor::class, ScalarJsonlProvider)
+        this.register(FloatDescriptor::class, ScalarJsonlProvider)
+        this.register(DoubleDescriptor::class, ScalarJsonlProvider)
+        this.register(StringDescriptor::class, ScalarJsonlProvider)
+
+        /* Vector descriptors. */
+        this.register(BooleanVectorDescriptor::class, VectorJsonlProvider)
+        this.register(IntVectorDescriptor::class, VectorJsonlProvider)
+        this.register(LongVectorDescriptor::class, VectorJsonlProvider)
+        this.register(FloatVectorDescriptor::class, VectorJsonlProvider)
+        this.register(DoubleVectorDescriptor::class, VectorJsonlProvider)
+
+        /* Struct descriptor. */
+        this.register(LabelDescriptor::class, StructJsonlProvider)
+        this.register(FileSourceMetadataDescriptor::class, StructJsonlProvider)
+        this.register(VideoSourceMetadataDescriptor::class, StructJsonlProvider)
+        this.register(TemporalMetadataDescriptor::class, StructJsonlProvider)
+        this.register(Rectangle2DMetadataDescriptor::class, StructJsonlProvider)
+        this.register(MediaDimensionsDescriptor::class, StructJsonlProvider)
+        this.register(MapStructDescriptor::class, StructJsonlProvider)
+    }
+
+}
\ No newline at end of file
diff --git a/vitrivr-engine-module-jsonl/src/main/kotlin/org/vitrivr/engine/database/jsonl/JsonlInitializer.kt b/vitrivr-engine-module-jsonl/src/main/kotlin/org/vitrivr/engine/database/jsonl/JsonlInitializer.kt
new file mode 100644
index 00000000..68b7a113
--- /dev/null
+++ b/vitrivr-engine-module-jsonl/src/main/kotlin/org/vitrivr/engine/database/jsonl/JsonlInitializer.kt
@@ -0,0 +1,46 @@
+package org.vitrivr.engine.database.jsonl
+
+import org.vitrivr.engine.core.database.descriptor.DescriptorInitializer
+import org.vitrivr.engine.core.model.descriptor.Descriptor
+import org.vitrivr.engine.core.model.metamodel.Schema
+import java.io.IOException
+import kotlin.io.path.*
+
+class JsonlInitializer<D : Descriptor>(
+    override val field: Schema.Field<*, D>,
+    connection: JsonlConnection
+) : DescriptorInitializer<D> {
+
+    private val path = connection.getPath(field)
+
+    override fun initialize() {
+        try {
+            path.parent.createDirectories()
+            path.createFile()
+        } catch (ioe: IOException) {
+            LOGGER.error(ioe) { "Cannot initialize '${path.absolutePathString()}'" }
+        } catch (se: SecurityException) {
+            LOGGER.error(se) { "Cannot initialize '${path.absolutePathString()}'" }
+        }
+
+    }
+
+    override fun deinitialize() {
+        try {
+            path.deleteIfExists()
+        } catch (ioe: IOException) {
+            LOGGER.error(ioe) { "Cannot deinitialize '${path.absolutePathString()}'" }
+        }
+    }
+
+    override fun isInitialized(): Boolean = path.exists()
+
+    override fun truncate() {
+        try {
+            path.deleteExisting()
+            path.createFile()
+        } catch (ioe: IOException) {
+            LOGGER.error(ioe) { "Cannot truncate '${path.absolutePathString()}'" }
+        }
+    }
+}
\ No newline at end of file
diff --git a/vitrivr-engine-module-jsonl/src/main/kotlin/org/vitrivr/engine/database/jsonl/JsonlWriter.kt b/vitrivr-engine-module-jsonl/src/main/kotlin/org/vitrivr/engine/database/jsonl/JsonlWriter.kt
new file mode 100644
index 00000000..44b5ca44
--- /dev/null
+++ b/vitrivr-engine-module-jsonl/src/main/kotlin/org/vitrivr/engine/database/jsonl/JsonlWriter.kt
@@ -0,0 +1,83 @@
+package org.vitrivr.engine.database.jsonl
+
+import kotlinx.serialization.encodeToString
+import kotlinx.serialization.json.Json
+import org.vitrivr.engine.core.database.descriptor.DescriptorWriter
+import org.vitrivr.engine.core.model.descriptor.Attribute
+import org.vitrivr.engine.core.model.descriptor.AttributeName
+import org.vitrivr.engine.core.model.descriptor.Descriptor
+import org.vitrivr.engine.core.model.metamodel.Schema
+import org.vitrivr.engine.core.model.types.Type
+import org.vitrivr.engine.core.model.types.Value
+import org.vitrivr.engine.database.jsonl.JsonlConnection.Companion.DESCRIPTOR_ID_COLUMN_NAME
+import org.vitrivr.engine.database.jsonl.JsonlConnection.Companion.RETRIEVABLE_ID_COLUMN_NAME
+import org.vitrivr.engine.database.jsonl.model.AttributeContainer
+import org.vitrivr.engine.database.jsonl.model.AttributeContainerList
+import java.nio.file.StandardOpenOption
+import kotlin.io.path.writer
+
+
+class JsonlWriter<D : Descriptor>(override val field: Schema.Field<*, D>, override val connection: JsonlConnection) :
+    DescriptorWriter<D>, AutoCloseable {
+
+    private val writer = connection.getPath(field).writer(Charsets.UTF_8, StandardOpenOption.APPEND)
+
+    override fun add(item: D): Boolean {
+
+        val valueMap = mutableMapOf<AttributeName, Value<*>?>(
+            DESCRIPTOR_ID_COLUMN_NAME to Value.UUIDValue(item.id),
+            RETRIEVABLE_ID_COLUMN_NAME to Value.UUIDValue(
+                item.retrievableId
+                    ?: throw IllegalArgumentException("A struct descriptor must be associated with a retrievable ID.")
+            )
+        )
+
+        valueMap.putAll(item.values())
+        val attributes = mutableListOf(
+            Attribute(DESCRIPTOR_ID_COLUMN_NAME, Type.UUID, false),
+            Attribute(RETRIEVABLE_ID_COLUMN_NAME, Type.UUID, false)
+        )
+        attributes.addAll(item.layout())
+
+        val list = AttributeContainerList(
+            attributes.map { attribute ->
+                AttributeContainer(
+                    attribute,
+                    valueMap[attribute.name]
+                )
+            }
+        )
+
+
+        writer.write(Json.encodeToString(list))
+        writer.write("\n")
+        writer.flush()
+
+        return true
+
+    }
+
+    override fun addAll(items: Iterable<D>): Boolean {
+        items.forEach { add(it) }
+        return true
+    }
+
+    override fun update(item: D): Boolean {
+        LOGGER.warn { "JsonlWriter.update is not supported" }
+        return false
+    }
+
+    override fun delete(item: D): Boolean {
+        LOGGER.warn { "JsonlWriter.delete is not supported" }
+        return false
+    }
+
+    override fun deleteAll(items: Iterable<D>): Boolean {
+        LOGGER.warn { "JsonlWriter.deleteAll is not supported" }
+        return false
+    }
+
+    override fun close() {
+        writer.close()
+    }
+}
\ No newline at end of file
diff --git a/vitrivr-engine-module-jsonl/src/main/kotlin/org/vitrivr/engine/database/jsonl/model/AttributeContainer.kt b/vitrivr-engine-module-jsonl/src/main/kotlin/org/vitrivr/engine/database/jsonl/model/AttributeContainer.kt
new file mode 100644
index 00000000..9c83cbd4
--- /dev/null
+++ b/vitrivr-engine-module-jsonl/src/main/kotlin/org/vitrivr/engine/database/jsonl/model/AttributeContainer.kt
@@ -0,0 +1,13 @@
+package org.vitrivr.engine.database.jsonl.model
+
+import kotlinx.serialization.Serializable
+import org.vitrivr.engine.core.model.descriptor.Attribute
+import org.vitrivr.engine.core.model.types.Value
+
+@Serializable
+data class AttributeContainer(val attribute: Attribute, val value: ValueContainer?) {
+    constructor(attribute: Attribute, value: Value<*>?) : this(
+        attribute,
+        if (value == null) null else ValueContainer.fromValue(value)
+    )
+}
diff --git a/vitrivr-engine-module-jsonl/src/main/kotlin/org/vitrivr/engine/database/jsonl/model/AttributeContainerList.kt b/vitrivr-engine-module-jsonl/src/main/kotlin/org/vitrivr/engine/database/jsonl/model/AttributeContainerList.kt
new file mode 100644
index 00000000..ae226f9a
--- /dev/null
+++ b/vitrivr-engine-module-jsonl/src/main/kotlin/org/vitrivr/engine/database/jsonl/model/AttributeContainerList.kt
@@ -0,0 +1,6 @@
+package org.vitrivr.engine.database.jsonl.model
+
+import kotlinx.serialization.Serializable
+
+@Serializable
+data class AttributeContainerList(val list: List<AttributeContainer>)
diff --git a/vitrivr-engine-module-jsonl/src/main/kotlin/org/vitrivr/engine/database/jsonl/model/JsonlRelationship.kt b/vitrivr-engine-module-jsonl/src/main/kotlin/org/vitrivr/engine/database/jsonl/model/JsonlRelationship.kt
new file mode 100644
index 00000000..efffd87e
--- /dev/null
+++ b/vitrivr-engine-module-jsonl/src/main/kotlin/org/vitrivr/engine/database/jsonl/model/JsonlRelationship.kt
@@ -0,0 +1,13 @@
+package org.vitrivr.engine.database.jsonl.model
+
+import kotlinx.serialization.Serializable
+import org.vitrivr.engine.core.model.relationship.Relationship
+import org.vitrivr.engine.core.model.retrievable.RetrievableId
+
+@Serializable
+data class JsonlRelationship(val sub: RetrievableId, val pred: String, val obj: RetrievableId) {
+    constructor(relationship: Relationship) : this(relationship.subjectId, relationship.predicate, relationship.objectId)
+
+    fun toTriple() : Triple<RetrievableId, String, RetrievableId> = Triple(sub, pred, obj)
+
+}
diff --git a/vitrivr-engine-module-jsonl/src/main/kotlin/org/vitrivr/engine/database/jsonl/model/JsonlRetrievable.kt b/vitrivr-engine-module-jsonl/src/main/kotlin/org/vitrivr/engine/database/jsonl/model/JsonlRetrievable.kt
new file mode 100644
index 00000000..0e9ac6d0
--- /dev/null
+++ b/vitrivr-engine-module-jsonl/src/main/kotlin/org/vitrivr/engine/database/jsonl/model/JsonlRetrievable.kt
@@ -0,0 +1,13 @@
+package org.vitrivr.engine.database.jsonl.model
+
+import kotlinx.serialization.Serializable
+import org.vitrivr.engine.core.model.retrievable.Retrievable
+import org.vitrivr.engine.core.model.retrievable.RetrievableId
+import org.vitrivr.engine.core.model.retrievable.Retrieved
+
+@Serializable
+data class JsonlRetrievable(val id: RetrievableId, val type: String) {
+    fun toRetrieved(): Retrieved = Retrieved(id, if (type.isEmpty()) null else type, false)
+
+    constructor(retrievable: Retrievable) : this(retrievable.id, retrievable.type ?: "")
+}
diff --git a/vitrivr-engine-module-jsonl/src/main/kotlin/org/vitrivr/engine/database/jsonl/model/ValueContainer.kt b/vitrivr-engine-module-jsonl/src/main/kotlin/org/vitrivr/engine/database/jsonl/model/ValueContainer.kt
new file mode 100644
index 00000000..aa135690
--- /dev/null
+++ b/vitrivr-engine-module-jsonl/src/main/kotlin/org/vitrivr/engine/database/jsonl/model/ValueContainer.kt
@@ -0,0 +1,116 @@
+package org.vitrivr.engine.database.jsonl.model
+
+import kotlinx.serialization.Serializable
+import org.vitrivr.engine.core.model.serializer.DateSerializer
+import org.vitrivr.engine.core.model.serializer.UUIDSerializer
+import org.vitrivr.engine.core.model.types.Value
+import java.util.*
+
+@Serializable
+sealed class ValueContainer {
+
+    companion object {
+        fun fromValue(value: Value<*>): ValueContainer = when (value) {
+            is Value.Boolean -> BooleanValueContainer(value.value)
+            is Value.Byte -> ByteValueContainer(value.value)
+            is Value.DateTime -> DateTimeValueContainer(value.value)
+            is Value.Double -> DoubleValueContainer(value.value)
+            is Value.Float -> FloatValueContainer(value.value)
+            is Value.Int -> IntValueContainer(value.value)
+            is Value.Long -> LongValueContainer(value.value)
+            is Value.Short -> ShortValueContainer(value.value)
+            is Value.String -> StringValueContainer(value.value)
+            is Value.Text -> TextValueContainer(value.value)
+            is Value.UUIDValue -> UuidValueContainer(value.value)
+            is Value.BooleanVector -> BooleanVectorValueContainer(value.value)
+            is Value.DoubleVector -> DoubleVectorValueContainer(value.value)
+            is Value.FloatVector -> FloatVectorValueContainer(value.value)
+            is Value.IntVector -> IntVectorValueContainer(value.value)
+            is Value.LongVector -> LongVectorValueContainer(value.value)
+        }
+    }
+
+    abstract fun toValue(): Value<*>
+
+}
+
+@Serializable
+class BooleanValueContainer(private val value: Boolean) : ValueContainer() {
+    override fun toValue(): Value<Boolean> = Value.Boolean(value)
+}
+
+@Serializable
+class ByteValueContainer(private val value: Byte) : ValueContainer() {
+    override fun toValue(): Value<Byte> = Value.Byte(value)
+}
+
+@Serializable
+class DateTimeValueContainer(@Serializable(DateSerializer::class) private val value: Date) :
+    ValueContainer() {
+    override fun toValue(): Value<Date> = Value.DateTime(value)
+}
+
+@Serializable
+class DoubleValueContainer(private val value: Double) : ValueContainer() {
+    override fun toValue(): Value<Double> = Value.Double(value)
+}
+
+@Serializable
+class FloatValueContainer(private val value: Float) : ValueContainer() {
+    override fun toValue(): Value<Float> = Value.Float(value)
+}
+
+@Serializable
+class IntValueContainer(private val value: Int) : ValueContainer() {
+    override fun toValue(): Value<Int> = Value.Int(value)
+}
+
+@Serializable
+class LongValueContainer(private val value: Long) : ValueContainer() {
+    override fun toValue(): Value<Long> = Value.Long(value)
+}
+
+@Serializable
+class ShortValueContainer(private val value: Short) : ValueContainer() {
+    override fun toValue(): Value<Short> = Value.Short(value)
+}
+
+@Serializable
+class StringValueContainer(private val value: String) : ValueContainer() {
+    override fun toValue(): Value<String> = Value.String(value)
+}
+
+@Serializable
+class TextValueContainer(private val value: String) : ValueContainer() {
+    override fun toValue(): Value<String> = Value.Text(value)
+}
+
+@Serializable
+class UuidValueContainer(@Serializable(UUIDSerializer::class) private val value: UUID) : ValueContainer() {
+    override fun toValue(): Value<UUID> = Value.UUIDValue(value)
+}
+
+@Serializable
+class BooleanVectorValueContainer(private val value: BooleanArray) : ValueContainer() {
+    override fun toValue(): Value<BooleanArray> = Value.BooleanVector(value)
+}
+
+@Serializable
+class DoubleVectorValueContainer(private val value: DoubleArray) : ValueContainer() {
+    override fun toValue(): Value<DoubleArray> = Value.DoubleVector(value)
+}
+
+@Serializable
+class FloatVectorValueContainer(private val value: FloatArray) : ValueContainer() {
+    override fun toValue(): Value<FloatArray> = Value.FloatVector(value)
+}
+
+@Serializable
+class IntVectorValueContainer(private val value: IntArray) : ValueContainer() {
+    override fun toValue(): Value<IntArray> = Value.IntVector(value)
+}
+
+@Serializable
+class LongVectorValueContainer(private val value: LongArray) : ValueContainer() {
+    override fun toValue(): Value<LongArray> = Value.LongVector(value)
+}
\ No newline at end of file
diff --git a/vitrivr-engine-module-jsonl/src/main/kotlin/org/vitrivr/engine/database/jsonl/retrievable/JsonlRetrievableInitializer.kt b/vitrivr-engine-module-jsonl/src/main/kotlin/org/vitrivr/engine/database/jsonl/retrievable/JsonlRetrievableInitializer.kt
new file mode 100644
index 00000000..97c46252
--- /dev/null
+++ b/vitrivr-engine-module-jsonl/src/main/kotlin/org/vitrivr/engine/database/jsonl/retrievable/JsonlRetrievableInitializer.kt
@@ -0,0 +1,45 @@
+package org.vitrivr.engine.database.jsonl.retrievable
+
+import org.vitrivr.engine.core.database.retrievable.RetrievableInitializer
+import org.vitrivr.engine.database.jsonl.JsonlConnection
+import org.vitrivr.engine.database.jsonl.LOGGER
+import java.io.IOException
+import kotlin.io.path.*
+
+class JsonlRetrievableInitializer(private val connection: JsonlConnection) : RetrievableInitializer {
+
+    private val retrievablePath = connection.schemaRoot.resolve("retrievables.jsonl")
+    private val connectionPath = connection.schemaRoot.resolve("retrievable_connections.jsonl")
+
+    override fun initialize() {
+        try {
+            connection.schemaRoot.createDirectories()
+            retrievablePath.createFile()
+            connectionPath.createFile()
+        } catch (ioe: IOException) {
+            LOGGER.error(ioe) { "Cannot initialize '${connection.schemaRoot.absolutePathString()}'" }
+        }
+    }
+
+    override fun deinitialize() {
+        try {
+            retrievablePath.deleteIfExists()
+            connectionPath.deleteIfExists()
+        } catch (ioe: IOException) {
+            LOGGER.error(ioe) { "Cannot delete '${connection.schemaRoot.absolutePathString()}'" }
+        }
+    }
+
+    override fun isInitialized(): Boolean = retrievablePath.exists() && connectionPath.exists()
+
+    override fun truncate() {
+        try {
+            retrievablePath.deleteIfExists()
+            retrievablePath.createFile()
+            connectionPath.deleteIfExists()
+            connectionPath.createFile()
+        } catch (ioe: IOException) {
+            LOGGER.error(ioe) { "Cannot truncate '${connection.schemaRoot.absolutePathString()}'" }
+        }
+    }
+}
\ No newline at end of file
diff --git a/vitrivr-engine-module-jsonl/src/main/kotlin/org/vitrivr/engine/database/jsonl/retrievable/JsonlRetrievableReader.kt b/vitrivr-engine-module-jsonl/src/main/kotlin/org/vitrivr/engine/database/jsonl/retrievable/JsonlRetrievableReader.kt
new file mode 100644
index 00000000..c9500365
--- /dev/null
+++ b/vitrivr-engine-module-jsonl/src/main/kotlin/org/vitrivr/engine/database/jsonl/retrievable/JsonlRetrievableReader.kt
@@ -0,0 +1,72 @@
+package org.vitrivr.engine.database.jsonl.retrievable
+
+import kotlinx.serialization.SerializationException
+import kotlinx.serialization.json.Json
+import org.vitrivr.engine.core.database.retrievable.RetrievableReader
+import org.vitrivr.engine.core.model.retrievable.Retrievable
+import org.vitrivr.engine.core.model.retrievable.RetrievableId
+import org.vitrivr.engine.database.jsonl.JsonlConnection
+import org.vitrivr.engine.database.jsonl.LOGGER
+import org.vitrivr.engine.database.jsonl.model.JsonlRelationship
+import org.vitrivr.engine.database.jsonl.model.JsonlRetrievable
+import java.io.BufferedReader
+import java.io.InputStreamReader
+import kotlin.io.path.inputStream
+
+class JsonlRetrievableReader(override val connection: JsonlConnection) : RetrievableReader {
+
+    private val retrievablePath = connection.schemaRoot.resolve("retrievables.jsonl")
+    private val connectionPath = connection.schemaRoot.resolve("retrievable_connections.jsonl")
+
+    override fun get(id: RetrievableId): Retrievable? = getAll().firstOrNull { it.id == id }
+
+    override fun exists(id: RetrievableId): Boolean = get(id) != null
+
+    override fun getAll(ids: Iterable<RetrievableId>): Sequence<Retrievable> {
+        val idSet = ids.toSet()
+        return getAll().filter { idSet.contains(it.id) }
+    }
+
+    override fun getConnections(
+        subjectIds: Collection<RetrievableId>,
+        predicates: Collection<String>,
+        objectIds: Collection<RetrievableId>
+    ): Sequence<Triple<RetrievableId, String, RetrievableId>> {
+        val subIds = subjectIds.toSet()
+        val predIds = predicates.toSet()
+        val objIds = objectIds.toSet()
+
+        return BufferedReader(InputStreamReader(connectionPath.inputStream())).lineSequence().mapNotNull {
+            try {
+                Json.decodeFromString<JsonlRelationship>(it)
+            } catch (se: SerializationException) {
+                LOGGER.error(se) { "Error during deserialization" }
+                null
+            } catch (ie: IllegalArgumentException) {
+                LOGGER.error(ie) { "Error during deserialization" }
+                null
+            }
+        }.filter {
+            (subIds.isEmpty() || subIds.contains(it.sub)) &&
+                    (predIds.isEmpty() || predIds.contains(it.pred)) &&
+                    (objIds.isEmpty() || objIds.contains(it.obj))
+        }.map { it.toTriple() }
+    }
+
+    override fun getAll(): Sequence<Retrievable> {
+        return BufferedReader(InputStreamReader(retrievablePath.inputStream())).lineSequence().mapNotNull {
+            try {
+                Json.decodeFromString<JsonlRetrievable>(it).toRetrieved()
+            } catch (se: SerializationException) {
+                LOGGER.error(se) { "Error during deserialization" }
+                null
+            } catch (ie: IllegalArgumentException) {
+                LOGGER.error(ie) { "Error during deserialization" }
+                null
+            }
+        }
+    }
+
+    override fun count(): Long = BufferedReader(InputStreamReader(retrievablePath.inputStream())).lineSequence().count().toLong()
+
+}
\ No newline at end of file
diff --git a/vitrivr-engine-module-jsonl/src/main/kotlin/org/vitrivr/engine/database/jsonl/retrievable/JsonlRetrievableWriter.kt b/vitrivr-engine-module-jsonl/src/main/kotlin/org/vitrivr/engine/database/jsonl/retrievable/JsonlRetrievableWriter.kt
new file mode 100644
index 00000000..fba04529
--- /dev/null
+++ b/vitrivr-engine-module-jsonl/src/main/kotlin/org/vitrivr/engine/database/jsonl/retrievable/JsonlRetrievableWriter.kt
@@ -0,0 +1,77 @@
+package org.vitrivr.engine.database.jsonl.retrievable
+
+import kotlinx.serialization.encodeToString
+import kotlinx.serialization.json.Json
+import org.vitrivr.engine.core.database.retrievable.RetrievableWriter
+import org.vitrivr.engine.core.model.relationship.Relationship
+import org.vitrivr.engine.core.model.retrievable.Retrievable
+import org.vitrivr.engine.database.jsonl.JsonlConnection
+import org.vitrivr.engine.database.jsonl.LOGGER
+import org.vitrivr.engine.database.jsonl.model.JsonlRelationship
+import org.vitrivr.engine.database.jsonl.model.JsonlRetrievable
+import java.io.File
+import java.io.FileWriter
+import java.nio.file.StandardOpenOption
+import kotlin.io.path.writer
+
+class JsonlRetrievableWriter(override val connection: JsonlConnection) : RetrievableWriter, AutoCloseable {
+
+    private val retrievableWriter = connection.schemaRoot.resolve("retrievables.jsonl").writer(Charsets.UTF_8, StandardOpenOption.APPEND)
+    private val connectionWriter = connection.schemaRoot.resolve("retrievable_connections.jsonl").writer(Charsets.UTF_8, StandardOpenOption.APPEND)
+
+    @Synchronized
+    override fun connect(relationship: Relationship): Boolean {
+        connectionWriter.write(Json.encodeToString(JsonlRelationship(relationship)))
+        connectionWriter.write("\n")
+        connectionWriter.flush()
+        return true
+    }
+
+    override fun connectAll(relationships: Iterable<Relationship>): Boolean {
+        relationships.forEach { connect(it) }
+        return true
+    }
+
+    override fun disconnect(relationship: Relationship): Boolean {
+        LOGGER.warn { "JsonlRetrievableWriter.disconnect is not supported" }
+        return false
+    }
+
+    override fun disconnectAll(relationships: Iterable<Relationship>): Boolean {
+        LOGGER.warn { "JsonlRetrievableWriter.disconnectAll is not supported" }
+        return false
+    }
+
+    @Synchronized
+    override fun add(item: Retrievable): Boolean {
+        retrievableWriter.write(Json.encodeToString(JsonlRetrievable(item)))
+        retrievableWriter.write("\n")
+        retrievableWriter.flush()
+        return true
+    }
+
+    override fun addAll(items: Iterable<Retrievable>): Boolean {
+        items.forEach { add(it) }
+        return true
+    }
+
+    override fun update(item: Retrievable): Boolean {
+        LOGGER.warn { "JsonlRetrievableWriter.update is not supported" }
+        return false
+    }
+
+    override fun delete(item: Retrievable): Boolean {
+        LOGGER.warn { "JsonlRetrievableWriter.delete is not supported" }
+        return false
+    }
+
+    override fun deleteAll(items: Iterable<Retrievable>): Boolean {
+        LOGGER.warn { "JsonlRetrievableWriter.deleteAll is not supported" }
+        return false
+    }
+
+    override fun close() {
+        retrievableWriter.close()
+        connectionWriter.close()
+    }
+}
\ No newline at end of file
diff --git a/vitrivr-engine-module-jsonl/src/main/kotlin/org/vitrivr/engine/database/jsonl/scalar/ScalarJsonlProvider.kt b/vitrivr-engine-module-jsonl/src/main/kotlin/org/vitrivr/engine/database/jsonl/scalar/ScalarJsonlProvider.kt
new file mode 100644
index 00000000..5e6e9b95
--- /dev/null
+++ b/vitrivr-engine-module-jsonl/src/main/kotlin/org/vitrivr/engine/database/jsonl/scalar/ScalarJsonlProvider.kt
@@ -0,0 +1,12 @@
+package org.vitrivr.engine.database.jsonl.scalar
+
+import org.vitrivr.engine.core.database.Connection
+import org.vitrivr.engine.core.database.descriptor.DescriptorReader
+import org.vitrivr.engine.core.model.descriptor.scalar.ScalarDescriptor
+import org.vitrivr.engine.core.model.metamodel.Schema
+import org.vitrivr.engine.database.jsonl.AbstractJsonlProvider
+import org.vitrivr.engine.database.jsonl.JsonlConnection
+
+object ScalarJsonlProvider: AbstractJsonlProvider<ScalarDescriptor<*>>() {
+    override fun newReader(connection: Connection, field: Schema.Field<*, ScalarDescriptor<*>>): DescriptorReader<ScalarDescriptor<*>> = ScalarJsonlReader(field, connection as JsonlConnection)
+}
\ No newline at end of file
diff --git a/vitrivr-engine-module-jsonl/src/main/kotlin/org/vitrivr/engine/database/jsonl/scalar/ScalarJsonlReader.kt b/vitrivr-engine-module-jsonl/src/main/kotlin/org/vitrivr/engine/database/jsonl/scalar/ScalarJsonlReader.kt
new file mode 100644
index 00000000..3f9eb154
--- /dev/null
+++ b/vitrivr-engine-module-jsonl/src/main/kotlin/org/vitrivr/engine/database/jsonl/scalar/ScalarJsonlReader.kt
@@ -0,0 +1,65 @@
+package org.vitrivr.engine.database.jsonl.scalar
+
+import org.vitrivr.engine.core.model.descriptor.scalar.*
+import org.vitrivr.engine.core.model.metamodel.Schema
+import org.vitrivr.engine.core.model.query.Query
+import org.vitrivr.engine.core.model.query.basics.ComparisonOperator
+import org.vitrivr.engine.core.model.query.bool.SimpleBooleanQuery
+import org.vitrivr.engine.core.model.query.fulltext.SimpleFulltextQuery
+import org.vitrivr.engine.core.model.retrievable.Retrieved
+import org.vitrivr.engine.core.model.types.Value
+import org.vitrivr.engine.database.jsonl.AbstractJsonlReader
+import org.vitrivr.engine.database.jsonl.model.AttributeContainerList
+import org.vitrivr.engine.database.jsonl.JsonlConnection
+import org.vitrivr.engine.database.jsonl.JsonlConnection.Companion.DESCRIPTOR_ID_COLUMN_NAME
+import org.vitrivr.engine.database.jsonl.JsonlConnection.Companion.RETRIEVABLE_ID_COLUMN_NAME
+
+class ScalarJsonlReader(
+    field: Schema.Field<*, ScalarDescriptor<*>>,
+    connection: JsonlConnection
+) : AbstractJsonlReader<ScalarDescriptor<*>>(field, connection) {
+
+    override fun toDescriptor(list: AttributeContainerList): ScalarDescriptor<*> {
+
+        val map = list.list.associateBy { it.attribute.name }
+        val retrievableId = (map[DESCRIPTOR_ID_COLUMN_NAME]?.value!!.toValue() as Value.UUIDValue).value
+        val descriptorId = (map[RETRIEVABLE_ID_COLUMN_NAME]?.value!!.toValue() as Value.UUIDValue).value
+        val value = map["value"]?.value!!.toValue()
+
+        return when (prototype) {
+            is BooleanDescriptor -> BooleanDescriptor(retrievableId, descriptorId, value as Value.Boolean)
+            is DoubleDescriptor -> DoubleDescriptor(retrievableId, descriptorId, value as Value.Double)
+            is FloatDescriptor -> FloatDescriptor(retrievableId, descriptorId, value as Value.Float)
+            is IntDescriptor -> IntDescriptor(retrievableId, descriptorId, value as Value.Int)
+            is LongDescriptor -> LongDescriptor(retrievableId, descriptorId, value as Value.Long)
+            is StringDescriptor -> StringDescriptor(retrievableId, descriptorId, value as Value.String)
+            else -> {
+                error("Unsupported type $prototype")
+            }
+        }
+
+    }
+
+    override fun query(query: Query): Sequence<ScalarDescriptor<*>> = when (query) {
+        is SimpleFulltextQuery -> this.queryFulltext(query)
+        is SimpleBooleanQuery<*> -> this.queryBoolean(query)
+        else -> throw UnsupportedOperationException("The provided query type ${query::class.simpleName} is not supported by this reader.")
+    }
+
+
+    private fun queryFulltext(fulltextQuery: SimpleFulltextQuery): Sequence<ScalarDescriptor<*>> {
+
+        val queryString = fulltextQuery.value.value
+        val attributeName = fulltextQuery.attributeName ?: return emptySequence()
+
+        return getAll().filter { descriptor ->
+            (descriptor.values()[attributeName]!! as Value.String).value.contains(queryString)
+        }
+
+    }
+
+    private fun queryBoolean(query: SimpleBooleanQuery<*>): Sequence<ScalarDescriptor<*>> =
+        getAll().filter { descriptor ->
+            query.comparison.compare(descriptor.value, query.value)
+        }
+}
diff --git a/vitrivr-engine-module-jsonl/src/main/kotlin/org/vitrivr/engine/database/jsonl/struct/StructJsonlProvider.kt b/vitrivr-engine-module-jsonl/src/main/kotlin/org/vitrivr/engine/database/jsonl/struct/StructJsonlProvider.kt
new file mode 100644
index 00000000..0d9a9b50
--- /dev/null
+++ b/vitrivr-engine-module-jsonl/src/main/kotlin/org/vitrivr/engine/database/jsonl/struct/StructJsonlProvider.kt
@@ -0,0 +1,12 @@
+package org.vitrivr.engine.database.jsonl.struct
+
+import org.vitrivr.engine.core.database.Connection
+import org.vitrivr.engine.core.database.descriptor.DescriptorReader
+import org.vitrivr.engine.core.model.descriptor.struct.StructDescriptor
+import org.vitrivr.engine.core.model.metamodel.Schema
+import org.vitrivr.engine.database.jsonl.AbstractJsonlProvider
+import org.vitrivr.engine.database.jsonl.JsonlConnection
+
+object StructJsonlProvider: AbstractJsonlProvider<StructDescriptor>() {
+    override fun newReader(connection: Connection, field: Schema.Field<*, StructDescriptor>): DescriptorReader<StructDescriptor> = StructJsonlReader(field, connection as JsonlConnection)
+}
\ No newline at end of file
diff --git a/vitrivr-engine-module-jsonl/src/main/kotlin/org/vitrivr/engine/database/jsonl/struct/StructJsonlReader.kt b/vitrivr-engine-module-jsonl/src/main/kotlin/org/vitrivr/engine/database/jsonl/struct/StructJsonlReader.kt
new file mode 100644
index 00000000..4bdcbc96
--- /dev/null
+++ b/vitrivr-engine-module-jsonl/src/main/kotlin/org/vitrivr/engine/database/jsonl/struct/StructJsonlReader.kt
@@ -0,0 +1,71 @@
+package org.vitrivr.engine.database.jsonl.struct
+
+import org.vitrivr.engine.core.model.descriptor.AttributeName
+import org.vitrivr.engine.core.model.descriptor.struct.StructDescriptor
+import org.vitrivr.engine.core.model.metamodel.Schema
+import org.vitrivr.engine.core.model.query.Query
+import org.vitrivr.engine.core.model.query.bool.SimpleBooleanQuery
+import org.vitrivr.engine.core.model.query.fulltext.SimpleFulltextQuery
+import org.vitrivr.engine.core.model.retrievable.Retrieved
+import org.vitrivr.engine.core.model.types.Value
+import org.vitrivr.engine.database.jsonl.AbstractJsonlReader
+import org.vitrivr.engine.database.jsonl.JsonlConnection
+import org.vitrivr.engine.database.jsonl.JsonlConnection.Companion.DESCRIPTOR_ID_COLUMN_NAME
+import org.vitrivr.engine.database.jsonl.JsonlConnection.Companion.RETRIEVABLE_ID_COLUMN_NAME
+import org.vitrivr.engine.database.jsonl.model.AttributeContainerList
+import org.vitrivr.engine.database.jsonl.retrievable.JsonlRetrievableReader
+import kotlin.reflect.full.primaryConstructor
+
+class StructJsonlReader(
+    field: Schema.Field<*, StructDescriptor>,
+    connection: JsonlConnection
+) : AbstractJsonlReader<StructDescriptor>(field, connection) {
+
+    override fun toDescriptor(list: AttributeContainerList): StructDescriptor {
+
+        val map = list.list.associateBy { it.attribute.name }
+        val constructor = this.field.analyser.descriptorClass.primaryConstructor
+            ?: throw IllegalStateException("Provided type ${this.field.analyser.descriptorClass} does not have a primary constructor.")
+        val valueMap = mutableMapOf<AttributeName, Value<*>>()
+
+        val retrievableId = (map[DESCRIPTOR_ID_COLUMN_NAME]?.value!!.toValue() as Value.UUIDValue).value
+        val descriptorId = (map[RETRIEVABLE_ID_COLUMN_NAME]?.value!!.toValue() as Value.UUIDValue).value
+        val parameters: MutableList<Any?> = mutableListOf(
+            descriptorId,
+            retrievableId,
+            valueMap,
+            this.field
+        )
+
+        prototype.layout().forEach { attribute ->
+            val value = map[attribute.name]!!.value?.toValue()!!
+            valueMap[attribute.name] = value
+        }
+
+        return constructor.call(*parameters.toTypedArray())
+    }
+
+    override fun query(query: Query): Sequence<StructDescriptor> = when (query) {
+        is SimpleFulltextQuery -> this.queryFulltext(query)
+        is SimpleBooleanQuery<*> -> this.queryBoolean(query)
+        else -> throw UnsupportedOperationException("The provided query type ${query::class.simpleName} is not supported by this reader.")
+    }
+
+
+    private fun queryFulltext(fulltextQuery: SimpleFulltextQuery): Sequence<StructDescriptor> {
+
+        val queryString = fulltextQuery.value.value
+        val attributeName = fulltextQuery.attributeName ?: return emptySequence()
+
+        return getAll().filter { descriptor ->
+            (descriptor.values()[attributeName]!! as Value.String).value.contains(queryString)
+        }
+
+    }
+
+    private fun queryBoolean(query: SimpleBooleanQuery<*>): Sequence<StructDescriptor> = getAll().filter { descriptor ->
+        query.comparison.compare(descriptor.values()[query.attributeName!!]!!, query.value)
+    }
+
+
+}
\ No newline at end of file
diff --git a/vitrivr-engine-module-jsonl/src/main/kotlin/org/vitrivr/engine/database/jsonl/vector/VectorJsonlProvider.kt b/vitrivr-engine-module-jsonl/src/main/kotlin/org/vitrivr/engine/database/jsonl/vector/VectorJsonlProvider.kt
new file mode 100644
index 00000000..4cb88c3c
--- /dev/null
+++ b/vitrivr-engine-module-jsonl/src/main/kotlin/org/vitrivr/engine/database/jsonl/vector/VectorJsonlProvider.kt
@@ -0,0 +1,12 @@
+package org.vitrivr.engine.database.jsonl.vector
+
+import org.vitrivr.engine.core.database.Connection
+import org.vitrivr.engine.core.database.descriptor.DescriptorReader
+import org.vitrivr.engine.core.model.descriptor.vector.VectorDescriptor
+import org.vitrivr.engine.core.model.metamodel.Schema
+import org.vitrivr.engine.database.jsonl.AbstractJsonlProvider
+import org.vitrivr.engine.database.jsonl.JsonlConnection
+
+object VectorJsonlProvider: AbstractJsonlProvider<VectorDescriptor<*>>() {
+    override fun newReader(connection: Connection, field: Schema.Field<*, VectorDescriptor<*>>): DescriptorReader<VectorDescriptor<*>> = VectorJsonlReader(field, connection as JsonlConnection)
+}
\ No newline at end of file
diff --git a/vitrivr-engine-module-jsonl/src/main/kotlin/org/vitrivr/engine/database/jsonl/vector/VectorJsonlReader.kt b/vitrivr-engine-module-jsonl/src/main/kotlin/org/vitrivr/engine/database/jsonl/vector/VectorJsonlReader.kt
new file mode 100644
index 00000000..79aae4f9
--- /dev/null
+++ b/vitrivr-engine-module-jsonl/src/main/kotlin/org/vitrivr/engine/database/jsonl/vector/VectorJsonlReader.kt
@@ -0,0 +1,130 @@
+package org.vitrivr.engine.database.jsonl.vector
+
+import org.vitrivr.engine.core.model.descriptor.vector.*
+import org.vitrivr.engine.core.model.metamodel.Schema
+import org.vitrivr.engine.core.model.query.Query
+import org.vitrivr.engine.core.model.query.basics.SortOrder
+import org.vitrivr.engine.core.model.query.proximity.ProximityQuery
+import org.vitrivr.engine.core.model.retrievable.Retrieved
+import org.vitrivr.engine.core.model.retrievable.attributes.DistanceAttribute
+import org.vitrivr.engine.core.model.types.Value
+import org.vitrivr.engine.core.util.knn.FixedSizePriorityQueue
+import org.vitrivr.engine.database.jsonl.AbstractJsonlReader
+import org.vitrivr.engine.database.jsonl.model.AttributeContainerList
+import org.vitrivr.engine.database.jsonl.JsonlConnection
+import org.vitrivr.engine.database.jsonl.JsonlConnection.Companion.DESCRIPTOR_ID_COLUMN_NAME
+import org.vitrivr.engine.database.jsonl.JsonlConnection.Companion.RETRIEVABLE_ID_COLUMN_NAME
+
+class VectorJsonlReader(
+    field: Schema.Field<*, VectorDescriptor<*>>,
+    connection: JsonlConnection
+) : AbstractJsonlReader<VectorDescriptor<*>>(field, connection) {
+
+    override fun toDescriptor(list: AttributeContainerList): VectorDescriptor<*> {
+
+        val map = list.list.associateBy { it.attribute.name }
+        val retrievableId = (map[RETRIEVABLE_ID_COLUMN_NAME]?.value!!.toValue() as Value.UUIDValue).value
+        val descriptorId = (map[DESCRIPTOR_ID_COLUMN_NAME]?.value!!.toValue() as Value.UUIDValue).value
+        val value = map["vector"]?.value!!.toValue()
+
+        return when (prototype) {
+            is BooleanVectorDescriptor -> BooleanVectorDescriptor(
+                descriptorId,
+                retrievableId,
+                value as Value.BooleanVector
+            )
+
+            is FloatVectorDescriptor -> FloatVectorDescriptor(
+                descriptorId,
+                retrievableId,
+                value as Value.FloatVector
+            )
+
+            is DoubleVectorDescriptor -> DoubleVectorDescriptor(
+                descriptorId,
+                retrievableId,
+                value as Value.DoubleVector
+            )
+
+            is IntVectorDescriptor -> IntVectorDescriptor(
+                descriptorId,
+                retrievableId,
+                value as Value.IntVector
+            )
+
+            is LongVectorDescriptor -> LongVectorDescriptor(
+                descriptorId,
+                retrievableId,
+                value as Value.LongVector
+            )
+        }
+    }
+
+    override fun query(query: Query): Sequence<VectorDescriptor<*>> = when (query) {
+        is ProximityQuery<*> -> queryProximity(query)
+        else -> throw UnsupportedOperationException("Query of typ ${query::class} is not supported by this reader.")
+    }
+
+    override fun queryAndJoin(query: Query): Sequence<Retrieved> = when (query) {
+        is ProximityQuery<*> -> queryAndJoinProximity(query)
+        else -> throw UnsupportedOperationException("Query of typ ${query::class} is not supported by this reader.")
+    }
+
+
+    private fun queryAndJoinProximity(query: ProximityQuery<*>): Sequence<Retrieved> {
+        val queue = knn(query)
+
+        val ids = queue.mapNotNull { it.first.retrievableId }
+
+        val retrievables = connection.getRetrievableReader().getAll(ids).associateBy { it.id }
+
+        return queue.map {
+            val retrieved = retrievables[it.first.retrievableId]!!
+            retrieved.addDescriptor(it.first)
+            retrieved.addAttribute(DistanceAttribute(it.second))
+            retrieved as Retrieved
+        }.asSequence()
+
+    }
+
+    private fun queryProximity(query: ProximityQuery<*>): Sequence<VectorDescriptor<*>> =
+        knn(query).asSequence().map { it.first }
+
+
+    private fun knn(query: ProximityQuery<*>): FixedSizePriorityQueue<Pair<VectorDescriptor<*>, Float>> {
+
+        val queue = FixedSizePriorityQueue(query.k.toInt(),
+            when (query.order) {
+                SortOrder.ASC -> Comparator<Pair<VectorDescriptor<*>, Float>> { p0, p1 ->
+                    p0.second.compareTo(p1.second)
+                }
+
+                SortOrder.DESC -> Comparator { p0, p1 ->
+                    p1.second.compareTo(p0.second)
+                }
+            }
+        )
+
+        getAll().forEach { descriptor ->
+            val dist = distance(query, descriptor.vector)
+            queue.add(descriptor to dist)
+        }
+
+        return queue
+
+    }
+
+    private fun distance(query: ProximityQuery<*>, vector: Value.Vector<*>): Float {
+        return when (query.value) {
+            is Value.FloatVector -> query.distance(query.value as Value.FloatVector, vector as Value.FloatVector)
+            is Value.DoubleVector -> query.distance(
+                query.value as Value.DoubleVector,
+                vector as Value.DoubleVector
+            ).toFloat()
+
+            else -> error("Unsupported query type ${query.value::class.simpleName}")
+        }
+    }
+
+
+}
\ No newline at end of file
diff --git a/vitrivr-engine-module-jsonl/src/main/resources/META-INF/services/org.vitrivr.engine.core.database.ConnectionProvider b/vitrivr-engine-module-jsonl/src/main/resources/META-INF/services/org.vitrivr.engine.core.database.ConnectionProvider
new file mode 100644
index 00000000..41cabd09
--- /dev/null
+++ b/vitrivr-engine-module-jsonl/src/main/resources/META-INF/services/org.vitrivr.engine.core.database.ConnectionProvider
@@ -0,0 +1 @@
+org.vitrivr.engine.database.jsonl.JsonlConnectionProvider
\ No newline at end of file
diff --git a/vitrivr-engine-module-jsonl/src/test/kotlin/org/vitrivr/engine/database/jsonl/descriptor/DescriptorInitializerTest.kt b/vitrivr-engine-module-jsonl/src/test/kotlin/org/vitrivr/engine/database/jsonl/descriptor/DescriptorInitializerTest.kt
new file mode 100644
index 00000000..37222081
--- /dev/null
+++ b/vitrivr-engine-module-jsonl/src/test/kotlin/org/vitrivr/engine/database/jsonl/descriptor/DescriptorInitializerTest.kt
@@ -0,0 +1,6 @@
+package org.vitrivr.engine.database.jsonl.descriptor
+
+import org.vitrivr.engine.core.database.descriptor.AbstractDescriptorInitializerTest
+
+
+class DescriptorInitializerTest : AbstractDescriptorInitializerTest("test-schema-jsonl.json")
\ No newline at end of file
diff --git a/vitrivr-engine-module-jsonl/src/test/kotlin/org/vitrivr/engine/database/jsonl/descriptor/struct/FileMetadataDescriptorReaderTest.kt b/vitrivr-engine-module-jsonl/src/test/kotlin/org/vitrivr/engine/database/jsonl/descriptor/struct/FileMetadataDescriptorReaderTest.kt
new file mode 100644
index 00000000..87d1c796
--- /dev/null
+++ b/vitrivr-engine-module-jsonl/src/test/kotlin/org/vitrivr/engine/database/jsonl/descriptor/struct/FileMetadataDescriptorReaderTest.kt
@@ -0,0 +1,6 @@
+package org.vitrivr.engine.database.jsonl.descriptor.struct
+
+import org.vitrivr.engine.core.database.descriptor.struct.AbstractFileMetadataDescriptorReaderTest
+
+
+class FileMetadataDescriptorReaderTest : AbstractFileMetadataDescriptorReaderTest("test-schema-jsonl.json")
\ No newline at end of file
diff --git a/vitrivr-engine-module-jsonl/src/test/kotlin/org/vitrivr/engine/database/jsonl/descriptor/vector/FloatVectorDescriptorReaderTest.kt b/vitrivr-engine-module-jsonl/src/test/kotlin/org/vitrivr/engine/database/jsonl/descriptor/vector/FloatVectorDescriptorReaderTest.kt
new file mode 100644
index 00000000..768645f0
--- /dev/null
+++ b/vitrivr-engine-module-jsonl/src/test/kotlin/org/vitrivr/engine/database/jsonl/descriptor/vector/FloatVectorDescriptorReaderTest.kt
@@ -0,0 +1,6 @@
+package org.vitrivr.engine.database.jsonl.descriptor.vector
+
+import org.vitrivr.engine.core.database.descriptor.vector.AbstractFloatVectorDescriptorReaderTest
+
+
+class FloatVectorDescriptorReaderTest : AbstractFloatVectorDescriptorReaderTest("test-schema-jsonl.json")
\ No newline at end of file
diff --git a/vitrivr-engine-module-jsonl/src/test/kotlin/org/vitrivr/engine/database/jsonl/retrievable/RetrievableInitializerTest.kt b/vitrivr-engine-module-jsonl/src/test/kotlin/org/vitrivr/engine/database/jsonl/retrievable/RetrievableInitializerTest.kt
new file mode 100644
index 00000000..872b96dd
--- /dev/null
+++ b/vitrivr-engine-module-jsonl/src/test/kotlin/org/vitrivr/engine/database/jsonl/retrievable/RetrievableInitializerTest.kt
@@ -0,0 +1,8 @@
+package org.vitrivr.engine.database.jsonl.retrievable
+
+import org.vitrivr.engine.core.database.retrievable.AbstractRetrievableInitializerTest
+
+
+class RetrievableInitializerTest : AbstractRetrievableInitializerTest("test-schema-jsonl.json") {
+
+}
\ No newline at end of file
diff --git a/vitrivr-engine-module-jsonl/src/test/kotlin/org/vitrivr/engine/database/jsonl/retrievable/RetrievableWriterTest.kt b/vitrivr-engine-module-jsonl/src/test/kotlin/org/vitrivr/engine/database/jsonl/retrievable/RetrievableWriterTest.kt
new file mode 100644
index 00000000..acaac7a1
--- /dev/null
+++ b/vitrivr-engine-module-jsonl/src/test/kotlin/org/vitrivr/engine/database/jsonl/retrievable/RetrievableWriterTest.kt
@@ -0,0 +1,7 @@
+package org.vitrivr.engine.database.jsonl.retrievable
+
+import org.vitrivr.engine.core.database.retrievable.AbstractRetrievableWriterTest
+
+class RetrievableWriterTest : AbstractRetrievableWriterTest("test-schema-jsonl.json") {
+
+}
\ No newline at end of file
diff --git a/vitrivr-engine-module-jsonl/src/test/resources/test-schema-jsonl.json b/vitrivr-engine-module-jsonl/src/test/resources/test-schema-jsonl.json
new file mode 100644
index 00000000..bd000f29
--- /dev/null
+++ b/vitrivr-engine-module-jsonl/src/test/resources/test-schema-jsonl.json
@@ -0,0 +1,42 @@
+{
+  "name": "vitrivr-test",
+  "connection": {
+    "database": "JsonlConnectionProvider",
+    "parameters": {
+      "root": "jsonl-test"
+    }
+  },
+  "fields": [
+    {
+      "name": "averagecolor",
+      "factory": "AverageColor"
+    },
+    {
+      "name": "file",
+      "factory": "FileSourceMetadata",
+      "indexes": [
+        {
+          "attributes": [
+            "path"
+          ],
+          "type": "FULLTEXT"
+        },
+        {
+          "attributes": [
+            "size"
+          ],
+          "type": "SCALAR"
+        }
+      ]
+    },
+    {
+      "name": "time",
+      "factory": "TemporalMetadata"
+    },
+    {
+      "name": "video",
+      "factory": "VideoSourceMetadata"
+    }
+  ],
+  "exporters": []
+}
diff --git a/vitrivr-engine-module-pgvector/src/main/kotlin/org/vitrivr/engine/database/pgvector/Utilities.kt b/vitrivr-engine-module-pgvector/src/main/kotlin/org/vitrivr/engine/database/pgvector/Utilities.kt
index 4c620286..8ff0258a 100644
--- a/vitrivr-engine-module-pgvector/src/main/kotlin/org/vitrivr/engine/database/pgvector/Utilities.kt
+++ b/vitrivr-engine-module-pgvector/src/main/kotlin/org/vitrivr/engine/database/pgvector/Utilities.kt
@@ -50,6 +50,7 @@ internal fun Type.toSql(): Int = when (this) {
     Type.Datetime -> JDBCType.DATE
     Type.String -> JDBCType.VARCHAR
     Type.Text -> JDBCType.CLOB
+    Type.UUID -> JDBCType.OTHER
     is Type.BooleanVector -> JDBCType.ARRAY
     is Type.DoubleVector -> JDBCType.ARRAY
     is Type.FloatVector -> JDBCType.ARRAY
diff --git a/vitrivr-engine-module-pgvector/src/main/kotlin/org/vitrivr/engine/database/pgvector/descriptor/PgDescriptorInitializer.kt b/vitrivr-engine-module-pgvector/src/main/kotlin/org/vitrivr/engine/database/pgvector/descriptor/PgDescriptorInitializer.kt
index 827a39a7..4e7879dd 100644
--- a/vitrivr-engine-module-pgvector/src/main/kotlin/org/vitrivr/engine/database/pgvector/descriptor/PgDescriptorInitializer.kt
+++ b/vitrivr-engine-module-pgvector/src/main/kotlin/org/vitrivr/engine/database/pgvector/descriptor/PgDescriptorInitializer.kt
@@ -54,6 +54,7 @@ open class PgDescriptorInitializer<D : Descriptor>(final override val field: Sch
                 Type.Float -> statement.append("\"${field.name}\" real, ")
                 Type.Double -> statement.append("\"${field.name}\" double precision, ")
                 Type.Datetime -> statement.append("\"${field.name}\" datetime, ")
+                Type.UUID -> statement.append("\"${field.name}\" uuid, ")
                 is Type.BooleanVector -> statement.append("\"${field.name}\" bit(${field.type.dimensions}), ")
                 is Type.DoubleVector -> statement.append("\"${field.name}\" vector(${field.type.dimensions}), ")
                 is Type.FloatVector -> statement.append("\"${field.name}\" vector(${field.type.dimensions}), ")
diff --git a/vitrivr-engine-module-pgvector/src/main/kotlin/org/vitrivr/engine/database/pgvector/descriptor/struct/StructDescriptorReader.kt b/vitrivr-engine-module-pgvector/src/main/kotlin/org/vitrivr/engine/database/pgvector/descriptor/struct/StructDescriptorReader.kt
index d9870e62..7ac1461b 100644
--- a/vitrivr-engine-module-pgvector/src/main/kotlin/org/vitrivr/engine/database/pgvector/descriptor/struct/StructDescriptorReader.kt
+++ b/vitrivr-engine-module-pgvector/src/main/kotlin/org/vitrivr/engine/database/pgvector/descriptor/struct/StructDescriptorReader.kt
@@ -65,6 +65,7 @@ class StructDescriptorReader(field: Schema.Field<*, StructDescriptor>, connectio
                 Type.Float -> result.getFloat(field.name).let { Value.Float(it) }
                 Type.Double -> result.getDouble(field.name).let { Value.Double(it) }
                 Type.Datetime -> result.getDate(field.name).toInstant().let { Value.DateTime(Date(it.toEpochMilli())) }
+                Type.UUID -> result.getObject(field.name, UUID::class.java).let { Value.UUIDValue(it) }
                 is Type.BooleanVector -> result.getObject(field.name, PgBitVector::class.java).toBooleanVector()
                 is Type.IntVector -> result.getObject(field.name, PgVector::class.java)?.toIntVector()
                 is Type.LongVector -> result.getObject(field.name, PgVector::class.java)?.toLongVector()