0.5.5-understand-c004

understand-c004

CALL NUMBER: deep_rollback.c004 : deep_isolation_level(1) DEFINITION: commit durability: the guaranteed persistence property that all writes of a committed transaction survive system crashes; realized via write-ahead log

Invoke this skill to understand c004 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 deep_isolation_level

• committed_data (d1): database state resulting from successfully completed transactions; constitutes the visible universe for read_committed queries

from deep_rollback

• c009 (d1): commit completion: the terminal state transition from active to committed; releases all locks held exclusively and schedules release of shared locks per protocol
• c003 (d2): commit sequence number (CSN): a monotonically incrementing identifier assigned to each committed transaction; provides total ordering of committed state changes
• c008 (d2): commit acknowledgment: the confirmation signal returned to the client indicating successful durable persistence of the transaction
• c010 (d2): commit promise: the contractual guarantee to the user that transaction effects are durable and will survive any subsequent system restart

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Projected from the database transaction isolation and concurrency control KB (280 concepts / 214 relations) — consistency-typed by MAP; the facet list after the colon IS the cross-lib dependency web.

(leaf — this is an actual skill.)