{"id":"lsm-no-concurrency-control","text":"The LSM tree in `lsm.py` has no locking, reference counting, or Version snapshots; `compact()` mutates `self._sstables` in place, so concurrent readers could see inconsistent state or reference deleted SSTables","truth_value":"IN","source":"entries/2026/05/29/topic-mvcc-version-snapshots.md","source_url":"","source_hash":"","justifications":[],"dependents":["lsm-compaction-safely-reduces-read-amplification"],"metadata":{},"created_at":"","updated_at":"","reviewed_at":"","verified_at":"","retracted_at":"","explanation":{"steps":[{"node":"lsm-no-concurrency-control","truth_value":"IN","reason":"premise"}]}}