Step 6: Create a global secondary index - Amazon DynamoDB

Step 6: Create a global secondary index

In this step, you create a global secondary index for the Music table that you created in Step 1: Create a table.

For more information about global secondary indexes, see Using Global Secondary Indexes in DynamoDB.

To use the Amazon DynamoDB console to create a global secondary index AlbumTitle-index for the Music table:

  1. Open the DynamoDB console at https://console.aws.amazon.com/dynamodb/.

  2. In the left navigation pane, choose Tables.

  3. Choose the Music table from the table list.

  4. Choose the Indexes tab for the Music table.

  5. Choose Create index.

  6. On the Create global secondary index page, do the following:

    1. For the Partition key, enter AlbumTitle.

    2. For Index name, enter AlbumTitle-index.

    3. Keep the default selection for the other settings on the page and choose Create index.

The following AWS CLI example creates a global secondary index AlbumTitle-index for the Music table using update-table.

Linux

aws dynamodb update-table \
    --table-name Music \
    --attribute-definitions AttributeName=AlbumTitle,AttributeType=S \
    --global-secondary-index-updates \
        "[{\"Create\":{\"IndexName\": \"AlbumTitle-index\",\"KeySchema\":[{\"AttributeName\":\"AlbumTitle\",\"KeyType\":\"HASH\"}], \
        \"ProvisionedThroughput\": {\"ReadCapacityUnits\": 10, \"WriteCapacityUnits\": 5      },\"Projection\":{\"ProjectionType\":\"ALL\"}}}]"

Windows CMD

aws dynamodb update-table ^
    --table-name Music ^
    --attribute-definitions AttributeName=AlbumTitle,AttributeType=S ^
    --global-secondary-index-updates "[{\"Create\":{\"IndexName\": \"AlbumTitle-index\",\"KeySchema\":[{\"AttributeName\":\"AlbumTitle\",\"KeyType\":\"HASH\"}], \"ProvisionedThroughput\": {\"ReadCapacityUnits\": 10, \"WriteCapacityUnits\": 5},\"Projection\":{\"ProjectionType\":\"ALL\"}}}]"

Using update-table returns the following sample result.

{
    "TableDescription": {
        "TableArn": "arn:aws:dynamodb:us-west-2:111122223333:table/Music",
        "AttributeDefinitions": [
            {
                "AttributeName": "AlbumTitle",
                "AttributeType": "S"
            },
            {
                "AttributeName": "Artist",
                "AttributeType": "S"
            },
            {
                "AttributeName": "SongTitle",
                "AttributeType": "S"
            }
        ],
        "GlobalSecondaryIndexes": [
            {
                "IndexSizeBytes": 0,
                "IndexName": "AlbumTitle-index",
                "Projection": {
                    "ProjectionType": "ALL"
                },
                "ProvisionedThroughput": {
                    "NumberOfDecreasesToday": 0,
                    "WriteCapacityUnits": 5,
                    "ReadCapacityUnits": 10
                },
                "IndexStatus": "CREATING", 
                "Backfilling": false,
                "KeySchema": [
                    {
                        "KeyType": "HASH",
                        "AttributeName": "AlbumTitle"
                    }
                ],
                "IndexArn": "arn:aws:dynamodb:us-west-2:111122223333:table/Music/index/AlbumTitle-index",
                "ItemCount": 0
            }
        ],
        "ProvisionedThroughput": {
            "NumberOfDecreasesToday": 0,
            "WriteCapacityUnits": 5,
            "ReadCapacityUnits": 10
        },
        "TableSizeBytes": 0,
        "TableName": "Music",
        "TableStatus": "UPDATING",
        "TableId": "a04b7240-0a46-435b-a231-b54091ab1017",
        "KeySchema": [
            {
                "KeyType": "HASH",
                "AttributeName": "Artist"
            },
            {
                "KeyType": "RANGE",
                "AttributeName": "SongTitle"
            }
        ],
        "ItemCount": 0,
        "CreationDateTime": 1558028402.69
    }
}

Note that the value of the IndexStatus field is set to CREATING.

To verify that DynamoDB has finished creating the AlbumTitle-index global secondary index, use the describe-table command.

Linux

 aws dynamodb describe-table --table-name Music | grep IndexStatus

Windows CMD

 aws dynamodb describe-table --table-name Music | findstr IndexStatus

This command returns the following result. The index is ready for use when the value of the IndexStatus field returned is set to ACTIVE. 

"IndexStatus": "ACTIVE",

Next, you can query the global secondary index. For details, see Step 7: Query the global secondary index.