Optimize db for multiple readers

Author: kclowes

tests/json_infra/helpers/fixture_db.py

@@ -362,8 +362,17 @@ def __init__(self, db_path: str = "tests/json_infra/fixtures.db"):
     def connect(self) -> sqlite3.Connection:
         """Connect to database."""
         if self.conn is None:
-            self.conn = sqlite3.connect(self.db_path, check_same_thread=False)
+            self.conn = sqlite3.connect(
+                self.db_path,
+                check_same_thread=False,
+                timeout=30.0,  # 30 second timeout for locks
+                uri=True,
+            )
             self.conn.row_factory = sqlite3.Row
+            # Read-only optimizations for concurrent access
+            self.conn.execute("PRAGMA query_only=1")
+            self.conn.execute("PRAGMA temp_store=MEMORY")
+            self.conn.execute("PRAGMA cache_size=-64000")  # 64MB cache
         return self.conn
 
     def fetch_state_tests(self, fork: str) -> Generator[Dict, None, None]:

tox.ini

@@ -59,11 +59,6 @@ commands =
         --basetemp="{temp_dir}/pytest" \
         src
 
-[testenv:build_fixture_db]
-description = Build the JSON fixture database
-commands =
-    python -m tests.json_infra.build_fixture_db
-
 [testenv:json_infra]
 description = Run the spec against released test fixtures
 passenv =