From 11b5e8b606d53a0ef4ccc6249f677d022d4acc7a Mon Sep 17 00:00:00 2001
From: Stef Vartolomeev <stef.vartolomeev@gmail.com>
Date: Fri, 15 Jul 2022 12:12:06 +0300
Subject: [PATCH] annotations: Add example of usage with Glboal Secondary
 Indexes

---
 .../README.md                                 | 31 +++++++++++++++++++
 1 file changed, 31 insertions(+)

diff --git a/packages/dynamodb-data-mapper-annotations/README.md b/packages/dynamodb-data-mapper-annotations/README.md
index 10a05ccc..a5321815 100644
--- a/packages/dynamodb-data-mapper-annotations/README.md
+++ b/packages/dynamodb-data-mapper-annotations/README.md
@@ -98,6 +98,37 @@ class BlogPost {
 }
 ```
 
+To declare Global Secondary Index (GSI) you should use the `indexKeyConfigurations` property of the `attribute` annotation:
+
+```typescript
+import {
+    attribute, 
+    hashKey,
+    table,
+} from '@aws/dynamodb-data-mapper-annotations';
+
+@table('posts')
+class BlogPost {
+    @hashKey()
+    id: string;
+
+    // define a GSI index named `authorIndex` that uses `author`` as partition key
+    @attribute({indexKeyConfigurations: {
+        authorIndex: 'HASH'
+    }})
+    author?: string;
+
+    // define a GSI index named `postedAtIndex` that uses `postedAt`` as sort key
+    @attribute({indexKeyConfigurations: {
+        postedAtIndex: 'RANGE'
+    }})
+    postedAt?: Date;
+
+    @attribute()
+    text?: string;
+}
+```
+
 ## Supported Annotations
 
 ### `attribute`