@startuml constraint-enforcement-strategies
!theme plain
title Constraint Enforcement Strategies

state "Operation Request" as Request
state "Immediate Validation" as Immediate
state "Deferred Validation" as Deferred
state "Execute Operation" as Execute
state "Transaction Commit" as Commit
state "Rollback" as Rollback
state "Success" as Success

Request --> Immediate: Strategy 1:\nEager
Request --> Execute: Strategy 2:\nDeferred

Immediate --> Execute: Valid
Immediate --> Rollback: Invalid

Execute --> Deferred: At commit
Deferred --> Commit: Valid
Deferred --> Rollback: Invalid

Commit --> Success
Rollback --> Request: Retry

note right of Immediate
  Immediate Checking:
  - Validate before execute
  - Simple reasoning
  - May reject valid intermediate states
  - Lower performance
end note

note right of Deferred
  Deferred Checking:
  - Validate at transaction end
  - Allows intermediate invalid states
  - Better performance
  - Complex error handling
end note

@enduml