business-logic-entry-point-transaction-isolation-levels
Transaction Isolation Levels for Business Logic Entry Points
Goal
When a business-logic entry point wraps its flow in a database transaction and follows Command-Query Separation, set the transaction isolation level based on whether the entry point is a command handler or a query handler, when the underlying persistence technology supports configurable isolation levels.
- Query handlers use the least blocking isolation level available in the project's database.
- Command handlers use REPEATABLE READ.
If the persistence technology does not support configurable isolation levels, this skill does not apply.
When This Skill Applies
This skill activates only when all four conditions are met:
- The entry point is a business-logic entry point.
- The entry point wraps its flow in a database transaction.
- The underlying persistence technology supports configurable isolation levels.
- The entry point follows Command-Query Separation, so it is classified as either a command handler or a query handler.
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