Can I upgrade schemas?

[theMistletoe]

Expected Behaviour

I’ve wrote schema setting on serverless.yml, and I’ve created one table by running migrate command.
After that, I wanna update schema about add GSI on that table, so I added settings about GSI on serverless.yml, and executed migrate command.

Actual Behaviour

But, not expected, table’s schema remains same state.

I can see below logs.

DynamoDB - Warn - table [tablename] already exists

Can I upgrade schemas, not deleting exsiting table, like sls deploy?