DOCSP-41143: Compound Indexes (#15)

Author: mcmorisi

source/includes/indexes/indexes.kt

@@ -12,7 +12,8 @@ data class Movie(
     @BsonId
     val id: ObjectId,
     val title: String? = "",
-    val genre: String? = "",
+    val type: String? = "",
+    val genres: List<String>? = null,
     val cast: List<String>? = null,
     val plot: String? = "",
 )
@@ -51,4 +52,21 @@ fun main() {
         println(result)
     }
     // end-index-single-query
+
+    // start-index-compound
+    collection.createIndex(Indexes.ascending(Movie::type.name, Movie::genres.name))
+    // end-index-compound
+
+    // start-index-compound-query
+    val filter = and(
+        eq(Movie::type.name, "movie"),
+        `in`(Movie::genres.name, "Drama")
+    )
+    val sort = Sorts.ascending(Movie::type.name, Movie::genres.name)
+    val results = collection.find(filter).sort(sort)
+
+    results.forEach { result ->
+        println(result)
+    }
+    // end-index-compound-query
 }

source/indexes/compound-index.txt

@@ -0,0 +1,98 @@
+.. _kotlin-sync-compound-index:
+
+================
+Compound Indexes
+================
+
+.. contents:: On this page
+   :local:
+   :backlinks: none
+   :depth: 2
+   :class: singlecol
+
+.. facet::
+   :name: genre
+   :values: reference
+ 
+.. meta::
+   :keywords: index, query, optimization, efficiency
+
+Overview
+--------
+
+:manual:`Compound indexes </core/index-compound/>` hold references to multiple
+fields within a collection's documents, improving query and sort performance.
+
+When creating a compound index, you must specify the following:
+
+- The fields on which to create the index
+- The sort order for each field (ascending or descending)
+
+Sample Data
+~~~~~~~~~~~
+
+The examples in this guide use the ``movies`` collection in the ``sample_mflix``
+database from the :atlas:`Atlas sample datasets </sample-data>`. To learn how to create a
+free MongoDB Atlas cluster and load the sample datasets, see the
+:atlas:`Get Started with Atlas </getting-started>` guide.
+
+The following {+language+} data class models the documents in this collection:
+
+.. literalinclude:: /includes/indexes/indexes.kt
+   :start-after: start-movie-class
+   :end-before: end-movie-class
+   :language: kotlin
+   :copyable:
+
+Create a Compound Index
+-----------------------
+
+The following example creates a compound index on the ``type`` and ``genre`` fields, with
+both fields indexed in ascending order:
+
+.. literalinclude:: /includes/indexes/indexes.kt
+   :start-after: start-index-compound
+   :end-before: end-index-compound
+   :language: kotlin
+   :copyable:
+   :dedent:
+
+The following is an example of a query that uses the index created in
+the preceding code sample:
+
+.. io-code-block::
+   :copyable: true
+
+   .. input:: /includes/indexes/indexes.kt
+      :start-after: start-index-compound-query
+      :end-before: end-index-compound-query
+      :language: kotlin
+      :dedent:
+   
+   .. output::
+      :visible: false
+
+      Movie(id=573a1392f29313caabcda755, title=China Seas, type=movie, genres=[Action, Drama, Adventure], ...)
+      Movie(id=573a1392f29313caabcd9ca6, title=Scarface, type=movie, genres=[Action, Crime, Drama], ... )
+      Movie(id=573a1392f29313caabcdb258, title=The Hurricane, type=movie, genres=[Action, Drama, Romance], ...)
+      Movie(id=573a1391f29313caabcd820b, title=Beau Geste, type=movie, genres=[Action, Adventure, Drama], ...)
+      ...
+
+Additional Information
+----------------------
+
+To learn more about compound indexes, see :manual:`Compound Indexes </core/index-compound>`
+in the {+mdb-server+} manual.
+
+To learn about effective indexing strategies using compound indexes, see
+:manual:`The ESR Rule </tutorial/equality-sort-range-rule>` in the {+mdb-server+} manual.
+
+API Documentation
+~~~~~~~~~~~~~~~~~
+
+To learn more about any of the methods discussed in this guide, see the following API
+documentation:
+
+- `find() <{+api+}/mongodb-driver-kotlin-sync/com.mongodb.kotlin.client/-mongo-collection/find.html>`__
+- `filter() <{+api+}/mongodb-driver-kotlin-sync/com.mongodb.kotlin.client/-find-iterable/filter.html>`__
+- `sort() <{+api+}/mongodb-driver-kotlin-sync/com.mongodb.kotlin.client/-find-iterable/sort.html>`__

source/indexes/single-field-index.txt

@@ -88,8 +88,8 @@ in the {+mdb-server+} manual.
 API Documentation
 ~~~~~~~~~~~~~~~~~
 
-To learn more about any of the methods or types discussed in this
-guide, see the following API Documentation:
+To learn more about any of the methods discussed in this guide, see the following API
+documentation:
 
 - `find() <{+api+}/mongodb-driver-kotlin-sync/com.mongodb.kotlin.client/-mongo-collection/find.html>`__
 - `filter() <{+api+}/mongodb-driver-kotlin-sync/com.mongodb.kotlin.client/-find-iterable/filter.html>`__

source/work-with-indexes.txt

@@ -20,6 +20,7 @@ Work with Indexes
 .. toctree::
 
    /indexes/single-field-index.txt
+   /indexes/compound-index.txt
 
 Overview
 --------
@@ -67,8 +68,8 @@ The following pages describe the most common index types and provide sample
 code for creating each index type.
 
 - :ref:`kotlin-sync-single-field-index`
+- :ref:`kotlin-sync-compound-index`
 
-.. TODO: - :ref:`kotlin-sync-compound-index`
 .. TODO: - :ref:`kotlin-sync-atlas-search-index`
 
 Remove an Index