0-1-3-understand-rollback

name	0.1.3-understand-rollback
description	[0.1.3] The act of undoing a transaction's effects using undo_log entries, returning the database to its pre-transacti

understand-rollback

CALL NUMBER: database_transaction_isolation_and_concurrency_c.rollback : deep_isolation_level(1) DEFINITION: The act of undoing a transaction's effects using undo_log entries, returning the database to its pre-transaction state.

Invoke this skill to understand rollback down to its primitives. The RELATIVE ROOT below is the least-fixed-point closure of everything it bundles from — the full import cone, grouped by the lib each prim comes from. Projected from a prover-typed KB (MAP/SWI-Prolog consistency gate): every reference below resolves.

THE RELATIVE ROOT (the import cone, by lib)

from database_transaction_isolation_and_concurrency_c

• aborted_state (d1): The terminal transaction_state after rollback completes; all acquired locks are released and the transaction cannot be restarted automatically.
• transaction_state (d1): The current phase of a transaction lifecycle: active, partially_committed, committed, aborted; drives lock release and recovery behavior.
• committed (d2): The terminal transaction_state after durable persistence of all changes; locks are released per locking_protocol rules.

from deep_isolation_level

• committed_data (d3): database state resulting from successfully completed transactions; constitutes the visible universe for read_committed queries

CONSUMERS (what needs this)

atomicity, before_image, compensation, compensation_action, database_transaction, transaction_boundary

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Projected from the database transaction isolation and concurrency control KB (217 concepts / 124 relations) — consistency-typed by MAP; the facet list after the colon IS the cross-lib dependency web.

(leaf — this is an actual skill.)