{"id":"mvcc-pattern-exists-at-row-level","text":"The codebase implements MVCC visibility (`ssi_database.py:_visible_value`, `mvcc_database.py:Version`) at the row/key level but not at the SSTable-file level where LevelDB uses Version reference counting for concurrent reader isolation","truth_value":"IN","source":"entries/2026/05/29/topic-mvcc-version-snapshots.md","source_url":"","source_hash":"","justifications":[],"dependents":[],"metadata":{},"explanation":{"steps":[{"node":"mvcc-pattern-exists-at-row-level","truth_value":"IN","reason":"premise"}]}}