I also have the same question. My service has a web transaction. When i explore the trace details of the transaction, i can see a detailed breakdown of calls to sub-components i.e call to the spring controller, multiple database calls. When i try to download this data through the API, I only get application level data (The app calls postgres and i can see a metric %like% 'Postgres/pg_catalog.pg_namespace/select'. I want to filter its data for the specific transaction as there are other api's within the same request that access postgres.) Do i need to look at events?