transaction_trace.account_ram_delta in v1.0.0

[aping]

I'm wondering how do I get account ram deltas in v1.0.0. In older version, there used to be this table action_trace_ram_delta where I can see ram deltas for each transaction. However with v1.0.0, the table is gone, and all I can see is this transaction_trace.account_ram_delta field, which:

1. it's type is chain.account_delta, which I assume should be chain.account_delta[], coz there should be multiple deltas within a transaction.
2. it's all empty