Feature Request: Support for Strict Schema Definition and/or Attribute Creation Responses

[jeremy302]

Description

The current schema-on-write data model is great for many use cases. However, this isn't always a desireable behavior for some projects.

I propose two potential features to address such use cases:

• Strict Schema Support: Add an option for strict schema enforcement. either on the db level or on a per-transaction basis.
  Transactions may error out or ignore unknown attributes.
• Attribute Creation Response: If in non-strict mode, transaction responses may contain info about attributes it created.

Use Cases and Benefits

1. Strict Schema: New projects can save the time and effort of having to enforce in user code.
2. Errors: Errors from the likes of inadvertent typos or incorrect data types can be caught early.
3. Attribute Creation Response: Knowing which new attributes were created during a transaction can help with debugging, auditing, and understanding the evolution of the data model.

[huahaiy]

We already have :closed-schema? option that errors out with unknown attributes, and :validate-data? option that throw if data type does not match schema. So the remaining issue is to add created attributes to the transaction report.

[jeremy302]

Indeed. :validate-date? and :closed-schema? provide the most important guardrails.