Fix #626: Use explicit DuckDB connections for thread-safe operations#627
Merged
javihern98 merged 2 commits intomainfrom Mar 25, 2026
Merged
Fix #626: Use explicit DuckDB connections for thread-safe operations#627javihern98 merged 2 commits intomainfrom
javihern98 merged 2 commits intomainfrom
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Replace duckdb.query() (shared default connection) with explicit
per-call duckdb.connect(":memory:") in Aggregation and Analytic
operators to prevent PendingRequest errors in multi-threaded usage.
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Summary
Fixes #626
Aggregation._agg_func()andAnalytic.analyticfunc()usedduckdb.query(), which operates on DuckDB's shared default in-process connection. This connection is not thread-safe — concurrent calls from multiple threads causePendingRequesterrors or deadlocks.Replaced
duckdb.query(query).to_df()with explicit per-callduckdb.connect(database=":memory:")connections in both operators, matching the pattern already used byEval._execute_query().Checklist
ruff format,ruff check,mypy)pytest)Impact / Risk
run()callsNotes
tests/Concurrency/test_thread_safety.pywith 5 tests covering concurrent aggregation, analytic, eval, mixed, and stress scenariosEval._execute_query()already used explicit connections — no changes needed there