AWS DynamoDB Free Tier - what happens when 25 RCU are exceeded?

Question

I am using the AWS free tier and I have 5 DynamoDB tables, each with 5 read/write capacities, although I am not sure I need 5 - I just use them for simple Lambda functions and there is definitely not much written and read.

What happens when I create a sixth table? Will the free 25 read/write capacities be automatically divided? Or will I have to lower the capacities on the other tables to be able to stay within the 25er capacity?

And what exactly happens when I lower the capacity (lets say to just 1)? There is definitely not mich happening, maybe 5-10 reads an hour.

Answer 1

As stated in AWS DynamoDB Pricing, you have 25 RCU and 25 WCU for free. It is up to you to decide the distribution among your tables. For example,

• ... you may have one table with 25 RCU and 25 WCU for free.
• ... you may have 25 tables, with 1 RCU and 1 WCU each, for free.

Each supplementary capacity unit will be paid, all it meters is the cumulative sum of all capacities.

If you have rare access to tables, I strongly advise you to lower your table's capacities as much as possible. 1 WCU and 1 RCU seems to work for you. If you notice any throttling, try 2 capacity units :)