# Task Log - Multi-tenant Data Isolation Implementation

## Actions
- Updated `lightrag/kg/json_kv_impl.py` to use `_get_composite_workspace` for directory isolation.
- Updated `lightrag/kg/postgres_impl.py` to use `_get_composite_workspace` in `initialize` method.
- Updated `lightrag/kg/mongo_impl.py` to use `_get_composite_workspace` in `__post_init__` for collection naming.
- Updated `lightrag/kg/redis_impl.py` to use `_get_composite_workspace` in `__post_init__` for key prefixing.
- Verified `lightrag/kg/json_doc_status_impl.py` was already updated.
- Verified `shared_storage.py` requires no changes as it relies on `final_namespace`.

## Decisions
- Applied `_get_composite_workspace` pattern consistently across all storage backends.
- For DBs with existing multi-tenant support (Mongo, Redis, Postgres), the new pattern adds an additional layer of isolation (namespace/collection level) which is beneficial for "Instance-per-tenant" deployments while remaining compatible with "Shared instance" deployments.
- Decided to keep `get_current_tenant_id()` logic in Mongo/Redis/Postgres as a fallback/complementary mechanism for shared instances.

## Next Steps
- Run tests to verify multi-tenant isolation works as expected (if tests were provided).
- Consider adding a migration script if existing data needs to be moved to new tenant-specific namespaces (out of scope for this task but good for future).

## Lessons/Insights
- Multi-tenancy implementation varies significantly between storage types (file-based vs DB).
- A unified `_get_composite_workspace` method in the base class is a powerful way to enforce consistency.
- Redundant isolation (row-level + collection-level) is acceptable and often desirable for security depth.
