How DynamoDB troughput works if case of partial writes?

Question

Suppose my document is of size 10 KB and I did an update of an attribute of size 1 KB. Does this mean I used 10 write unit or 1 write unit?

Answer 1

When performing a partial write of an object in DynamoDB it will consume the write capacity of the entire object, not just just the size of the attributes that is being written.

In the example you provided it would consume 10 write capacity.

Note: I was unable to locate this bit of information in the documentation, but have verified this experimentally on my own.