{"id":"gc-not-thread-safe","text":"`garbage_collect()` mutates `_versions` (replacing lists and deleting keys) without synchronization, assuming single-threaded execution — concurrent reads or writes during GC would race on the dict and its lists.","truth_value":"OUT","source":"entries/2026/05/29/snapshot-isolation-mvcc_database-garbage_collect.md","source_url":"","source_hash":"","justifications":[],"dependents":["multiple-core-components-assume-single-thread-silently","ssi-isolation-holds-under-single-thread"],"metadata":{"_retracted":true},"created_at":"","updated_at":"","reviewed_at":"","verified_at":"","retracted_at":"","explanation":{"steps":[{"node":"gc-not-thread-safe","truth_value":"OUT","reason":"retracted premise"}]}}