{"schema_version":1,"experiment_id":"eoa_inverse_innovation_exp09_archetype_breadth150_20260804","cell_id":"layer_decay_and_expiration_management__computer_science","arm":"BREADTH_PROBE_ONE_SHOT","candidate_id":"layer_decay_and_expiration_management__computer_science__P1","proposal_index":1,"version":0,"title":"Dependency-Safe Expiration of Database Migration Chains","problem":"An application accumulates ordered database migration scripts across releases. Even after every supported database instance has advanced beyond an old prefix, that prefix remains executable by default because it also embodies upgrade history, audit evidence, and reconstruction knowledge. As its original tooling and assumptions disappear, retaining the prefix in the active migration path can make new-environment initialization or recovery brittle; deleting it ad hoc can strand an overlooked deployment or erase evidence needed to explain past transformations.","actors":["Database platform owner","Application maintainers who author migrations","Deployment and recovery automation","Operators responsible for registered database instances","Audit or incident-response reviewers"],"observable_state":"A migration registry shows a long ordered prefix whose scripts predate the oldest registered database version, while fresh-database tests still execute that prefix and encounter removed dependencies, obsolete commands, or assumptions no longer represented in current code. The repository does not distinguish active migrations from archived evidence, held exceptions, or superseded steps.","consequence":"Database initialization and recovery remain coupled to obsolete executable history, while maintainers cannot safely bound the active chain because they lack proof that no supported upgrade path, reconstruction procedure, or audit obligation still depends on the old migrations.","affected_objective":"Keep database initialization and supported upgrades reproducible and maintainable while preserving required lineage, rollback evidence, and historical interpretation.","intervention":"Install a lifecycle manifest over the migration chain. Give each migration a stable identity, checksum, provenance, order, affected objects, and known dependencies; record the earliest version of every registered database and any preservation hold. A migration prefix becomes eligible for expiration only when all supported instances are beyond a proposed checkpoint and a disposable restore test proves that a signed schema baseline plus the remaining suffix reproduces defined schema and data invariants. Eligible scripts first leave the active runner through a quarantine state, remain in an immutable archive with a supersession tombstone, and are reviewed again before any later deletion decision.","structural_mapping":[{"archetype_element":"Sequentially accumulated layers","domain_realization":"Ordered database migration scripts and their execution records deposited by successive application releases."},{"archetype_element":"Layer inventory and age index","domain_realization":"A manifest containing migration identifier, sequence position, commit, checksum, author, execution prerequisites, affected objects, and deployment-version coverage."},{"archetype_element":"Retention policy matrix","domain_realization":"Rules linking migration classes to supported upgrade origins, incident-reconstruction needs, contractual retention, and explicit preservation holds."},{"archetype_element":"Decay or expiration trigger","domain_realization":"A prefix becomes review-eligible when every registered supported database is beyond its endpoint and current bootstrap tooling can replace it with a validated checkpoint."},{"archetype_element":"Dependency and reconstruction check","domain_realization":"Fleet-version inspection plus a disposable test that initializes from the checkpoint, replays the retained suffix, and compares declared schema and data invariants."},{"archetype_element":"Differentiated disposition path","domain_realization":"Keep active, repair and revalidate, preserve by exception, compact into a signed baseline, quarantine outside the active runner, archive, or eventually delete."},{"archetype_element":"Preservation exception register","domain_realization":"Named holds for unregistered-but-supported installations, litigation or audit needs, incident investigations, and migrations whose data semantics are not captured by the checkpoint."},{"archetype_element":"Deletion audit and rollback window","domain_realization":"A quarantine interval, immutable archive, signed checkpoint, decision record, and reversible manifest change before irreversible removal is considered."}],"mechanism_mapping":[{"mechanism_slug":"dependency_safe_delete_check","role":"Blocks expiration unless no supported database needs the prefix for upgrade and checkpoint reconstruction passes defined invariants.","counterfactual_removal":"Age alone could retire a migration still required by an overlooked deployment or recovery path."},{"mechanism_slug":"soft_delete_quarantine_window","role":"Removes an eligible prefix from normal migration execution while retaining an immediate path to reactivate it.","counterfactual_removal":"The first operational mistake would require reconstructing scripts from archival storage during an incident."},{"mechanism_slug":"tombstone_or_deletion_marker","role":"Leaves a manifest entry identifying the superseded migration range, replacement checkpoint, archive location, checksums, and authorizing decision.","counterfactual_removal":"References to retired migration identifiers could become unexplained gaps, weakening lineage and diagnosis."},{"mechanism_slug":"archive_restore_test","role":"Tests the archived prefix and replacement checkpoint in a disposable environment before and during the quarantine period.","counterfactual_removal":"The archive could provide nominal retention without demonstrated recoverability or equivalence."}],"causal_chain":["Each release deposits another ordered migration layer into the executable chain.","The supported database fleet advances, but old layers remain active because upgrade dependency and preservation status are not explicitly represented.","Tooling, code, and environmental assumptions used by old migrations change or disappear.","Fresh initialization and recovery continue traversing obsolete executable layers, while maintainers hesitate to remove them because hidden dependencies are plausible.","The lifecycle manifest makes age, fleet position, dependencies, holds, and reconstruction value observable per migration.","A fleet-state check and checkpoint reconstruction test gate expiration of an old prefix.","Quarantine, archival, tombstones, and rollback evidence demote obsolete layers without immediately destroying historical memory.","Periodic revalidation keeps both the active chain and its exceptions from growing indefinitely by default."],"baseline":"Keep every migration script indefinitely in the active execution path, occasionally repairing old scripts or manually squashing the chain when bootstrap failures or maintenance pressure become acute.","nearest_rivals":["Ad hoc migration squashing: replaces a historical prefix with a baseline but lacks a continuing retention-state model, exception register, quarantine window, and revalidation cadence.","Schema-only dump initialization: accelerates fresh setup but does not establish whether historical data transformations, supported upgrades, or audit reconstruction still depend on old migrations.","Migration linting and immutable-history rules: improve individual script quality and integrity but do not decide when layers should leave the active path.","Deleting migrations after a calendar cutoff: bounds the chain by age without proving fleet independence or reconstructability."],"remaining_contrastive_claim":"The candidate is specifically a governed lifecycle for executable migration layers: eligibility depends jointly on supported-fleet position, reconstruction evidence, and preservation obligations, and expiration changes a layer's state through checkpointing, quarantine, archival, and tombstoning. Its defining move is not merely producing a schema snapshot, validating scripts, or shortening the chain.","authority_safety":{"decision_authority":"The database platform owner may approve lifecycle-state changes for migrations only within the application's documented support policy; application owners and designated audit or incident custodians must approve exceptions relevant to their obligations.","authorized_first_step":"Create a read-only manifest and run a checkpoint reconstruction experiment for one noncritical service in disposable infrastructure; no migration is removed from an active runner.","excluded_actions":["Deleting or rewriting migration history","Changing any production database schema or data","Dropping support for a database instance or upgrade origin","Overriding audit, legal, incident, or contractual holds","Treating an unregistered instance as unsupported without an authorized support decision"],"halt_rollback":"Halt if any supported instance is at or before the proposed checkpoint, dependency ownership is unresolved, archive verification fails, or reconstructed invariants differ. Restore the prior lifecycle manifest, keep the original prefix active, and retain all generated evidence for diagnosis."},"negative_tests":{"strongest_counterevidence":"An old migration may encode a data transformation, provenance fact, or recovery procedure that a schema-equivalent checkpoint cannot reproduce; fleet registration may also omit supported installations.","problem_falsifier":"The problem is absent if the service has no accumulated executable migration chain, or if every environment already initializes from an independently validated baseline and no supported upgrade, recovery, audit, or lineage process traverses historical migrations.","intervention_falsifier":"The intervention fails if a checkpoint plus retained suffix cannot reproduce the declared invariants, if supported databases cannot be completely enumerated, or if quarantining an eligible prefix does not reduce reliance on obsolete scripts because other operational paths still execute them.","risks":["An unregistered supported database could be stranded by expiration.","Schema comparison could miss historical data semantics or external side effects.","Archive corruption or inaccessible encryption keys could defeat recovery.","A migration runner could ignore tombstones and execute an unintended path.","Preservation exceptions could become permanent unmanaged holds.","Checkpoint generation could conceal a compromised or incorrect historical state."]},"next_evidence_step":"For one noncritical service, inventory its migration chain and currently registered database versions, identify a single candidate prefix ending before the oldest supported instance, construct a signed checkpoint in a disposable database, replay the retained suffix, and compare schema objects plus a predeclared set of data invariants. Record unresolved dependencies and holds; do not quarantine or delete any script during this step.","prior_art_status":"UNSEARCHED","diversity_from_prior_proposals":"Not compared with other proposals under runtime isolation; this one-shot candidate focuses on executable database migration prefixes whose retirement must preserve supported upgrade paths and historical reconstruction.","revision_record":{"parent_version":null,"progress_targets_addressed":[],"conceptual_changes":[],"operational_changes":[],"evidence_changes":[],"claim_changes":[]}}