04 Try it yourself Interactive

Two clients, one seat

Both clients read a free seat. Compare an unconditional update with a conditional claim. This is a serialized trace of the important database events.

Check then write
Small deterministic teaching model
Choose a preset, predict the outcome, then use Next, Back or Reset. No steps autoplay.
A and B read the initial seat mapA claims F7 and commitsB writes, or rechecks eligibility after waitinginspect both user-visible outcomes
Press Next to work through it one step at a time.
A result–
B result–
Stored owner–
Claims reported–
step 0 / 0