From 1488e01bf911b9ffe25f89a86e495264f7384d44 Mon Sep 17 00:00:00 2001
From: ZdenekSrotyr <zdenek.srotyr@keboola.com>
Date: Thu, 9 Apr 2026 07:00:19 +0200
Subject: [PATCH] feat: add temp-file swap to BigQuery extractor

Write to extract.duckdb.tmp, then atomically swap into place with WAL cleanup.
Prevents lock conflicts with orchestrator holding read lock on existing database.
---
 connectors/bigquery/extractor.py | 12 ++++++++++++
 1 file changed, 12 insertions(+)

diff --git a/connectors/bigquery/extractor.py b/connectors/bigquery/extractor.py
index efbdafc..7917052 100644
--- a/connectors/bigquery/extractor.py
+++ b/connectors/bigquery/extractor.py
@@ -112,6 +112,18 @@ def init_extract(
     finally:
         conn.close()
 
+    # Atomic swap with WAL cleanup
+    old_wal = Path(str(db_path) + ".wal")
+    if old_wal.exists():
+        old_wal.unlink()
+
+    if tmp_db_path.exists():
+        shutil.move(str(tmp_db_path), str(db_path))
+
+    tmp_wal = Path(str(tmp_db_path) + ".wal")
+    if tmp_wal.exists():
+        tmp_wal.unlink()
+
     return stats