If you are using the Serverless Framework, you can create DynamodDB and add one GSI (Global Secondary Index) with cloudformation syntax.
How to add table: https://www.serverless.com/framework/docs/providers/aws/guide/resources/#configuration
Here is the syntax to add GSI: https://cloudkatha.com/solved-cannot-perform-more-than-one-gsi-creation-or-deletion-in-a-single-update/
Official docs related to GSI cloudformation syntax: https://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/aws-properties-dynamodb-gsi.html
That’s all fine until you need to add another GSI. You can’t do that with Cloudformation syntax [1]. Luckily we can do that programatically with Node.js (you could also use another programming language and just use the related aws-sdk library: https://aws.amazon.com/tools/
Here is the code snippet to create a new GSI on an existing DynamodDB table.
The AttributeDefinitions need to reflect the new GSI, not the existing table.
const {
DynamoDBClient,
UpdateTableCommand,
} = require("@aws-sdk/client-dynamodb");
const tableName = "YOUR DYNAMODB TABLE NAME GOES HERE";
const region = "YOUR REGION, e.g. us-east-1";
const accessKeyId = "Your api user access key with access to dynamodb";
const secretAccessKey = "Your api user access secret";
(async () => {
const config = {
region,
credentials: {
accessKeyId,
secretAccessKey,
},
};
console.log(config);
const client = new DynamoDBClient(config);
const params = {
TableName: tableName,
AttributeDefinitions: [
{ AttributeName: "sk", AttributeType: "S" },
{ AttributeName: "pk", AttributeType: "S" },
],
GlobalSecondaryIndexUpdates: [
{
Create: {
IndexName: "sk-pk-index",
KeySchema: [
{ AttributeName: "sk", KeyType: "HASH" },
{ AttributeName: "pk", KeyType: "RANGE" },
],
Projection: { ProjectionType: "ALL" },
ProvisionedThroughput: {
ReadCapacityUnits: 1,
WriteCapacityUnits: 1,
},
},
},
],
};
const command = new UpdateTableCommand(params);
try {
await client.send(command);
} catch (e) {
console.error(e);
}
console.log(JSON.stringify(command));
})();