Thread-safety: _subqueries dict in Compiler is not thread-safe #3
Description
Problem
data_diff/databases/base.py:109 — The _subqueries dictionary in the Compiler class is mutated during query compilation without synchronization.
Impact
Race condition risk in multi-threaded usage, which is common in data-diff's parallel comparison mode.
Suggested Fix
Use a thread-local or add locking around _subqueries access.
References
- File:
data_diff/databases/base.py, line 109