How acid transactions works

Move funds between two simulated accounts. Inspect private changes, concurrent reads, commit acknowledgement and crash recovery.

When to use it

Group related database updates so an interrupted workflow does not leave a partially applied business operation.

Explore the tradeoffs

A collection of successful statements is not automatically one atomic transaction. Grouping protects the invariant but introduces a commit boundary.

Isolation governs observations of unfinished work. Preventing dirty reads does not imply full serializability.

Atomicity and durability protect different failure boundaries. Waiting for durable storage costs work on the acknowledgement path.

Model boundaries

One writer and one observer, with simplified durable snapshots standing in for a recovery log. Read-uncommitted is a generic SQL-level illustration; PostgreSQL maps it to read-committed. Locking, serialization conflicts and distributed transactions are not simulated.