How to update multiple items in a DynamoDB table at once

Question

I\'m using DynamoDB and I need to update a specific attribute on multiple records. Writing my requirement in pseudo-language I would like to do an update that says \"update

Answer 1

DynamoDb is not designed as relational DB to support the native transaction. It is better to design the schema to avoid the situation of multiple updates at the first place. Or if it is not practical in your case, please keep in mind you may improve it when restructuring the design.

The only way to update multiple items at the same time is use TransactionWrite operation provided by DynamoDB. But it comes with a limitation (25 at most for example). So keep in mind with that, you probable should do some limitation in your application as well. In spite of being very costly (because of the implementation involving some consensus algorithm), it is still mush faster than a simple loop. And it gives you ACID property, which is probably we need most. Think of a situation using loop, if one of the updates fails, how do you deal with the failure? Is it possible to rollback all changes without causing some race condition? Are the updates idempotent? It really depends on the nature of your application of cause. Be careful.

Another option is to use the thread pool to do the network I/O job, which can definitely save a lot of time, but it also has the same failure-and-rollback issue to think about.