What is the recommended way to delete a large number of items from DynamoDB?

Question

I\'m writing a simple logging service in DynamoDB.

I have a logs table that is keyed by a user_id hash and a timestamp (Unix epoch int) range.

When a user of

Answer 1

I'm dropping this again.

Here's a lambda I did in nodeJS. It will perform a full scan on the table, then batch delete every 25 items per request.

Remember to change TABLE_NAME.

const AWS = require('aws-sdk');

const docClient = new AWS.DynamoDB.DocumentClient({ apiVersion: '2012-08-10' });

//const { TABLE_NAME } = process.env;
TABLE_NAME = "CHANGE ME PLEASE"

exports.handler = async (event) => {
    let params = {
        TableName: TABLE_NAME,
    };

    let items = [];
    let data = await docClient.scan(params).promise();
    items = [...items, ...data.Items];

    while (typeof data.LastEvaluatedKey != 'undefined') {
        params.ExclusiveStartKey = data.LastEvaluatedKey;

        data = await docClient.scan(params).promise();
        items = [...items, ...data.Items];
    }

    let leftItems = items.length;
    let group = [];
    let groupNumber = 0;

    console.log('Total items to be deleted', leftItems);

    for (const i of items) {
        const deleteReq = {
            DeleteRequest: {
                Key: {
                    id: i.id,
                },
            },
        };

        group.push(deleteReq);
        leftItems--;

        if (group.length === 25 || leftItems < 1) {
            groupNumber++;

            console.log(`Batch ${groupNumber} to be deleted.`);

            const params = {
                RequestItems: {
                    [TABLE_NAME]: group,
                },
            };

            await docClient.batchWrite(params).promise();

            console.log(
                `Batch ${groupNumber} processed. Left items: ${leftItems}`
            );

            // reset
            group = [];
        }
    }

    const response = {
        statusCode: 200,
        //  Uncomment below to enable CORS requests
        //  headers: {
        //      "Access-Control-Allow-Origin": "*"
        //  },
        body: JSON.stringify('Hello from Lambda!'),
    };
    return response;
};