问题
In my Android app I use Amazon DynamoDB. I created 10 tables with Read capacity 10 and Write capacity 5. Today I received an email from Amazon. It costs me 11.36$.
I don't understand the meaning of free tier. Here is what I read from Amazon:
DynamoDB customers get 25 GB of free storage, as well as up to 25 write capacity units and 25 read capacity units of ongoing throughput capacity (enough throughput to handle up to 200 million requests per month) and 2.5 million read requests from DynamoDB Streams for free.
Please tell me more clearly about the meaning of free tier: 25 read and 25 write capacity units!
回答1:
Amazon consider aggregates of read and write capacity of all tables, not the capacity of individual tables.
In your case the read capacity is 100 and the write capacity if 50. And you are charged for the 75 read capacity usage hours and 25 write capacity of usage hours.
Please plan properly for the read and write capacity of each table, otherwise you end up paying more bills.
Thanks.
来源：https://stackoverflow.com/questions/32373499/what-is-the-meaning-of-amazondb-free-tier