feat: harden long-range batch queries with redis+parquet caching

tests/test_database_slow_pool.py

@@ -0,0 +1,101 @@
+# -*- coding: utf-8 -*-
+"""Unit tests for isolated slow-query pool path."""
+
+from __future__ import annotations
+
+from unittest.mock import MagicMock, patch
+
+import mes_dashboard.core.database as db
+
+
+@patch.object(db, "oracledb")
+@patch.object(db, "get_slow_engine")
+@patch.object(db, "_get_slow_query_semaphore")
+@patch.object(db, "get_db_runtime_config")
+def test_read_sql_df_slow_uses_slow_pool_when_enabled(
+    mock_runtime,
+    mock_sem_fn,
+    mock_get_slow_engine,
+    mock_oracledb,
+):
+    """Slow query should checkout connection from isolated slow pool."""
+    mock_runtime.return_value = {
+        "slow_pool_enabled": True,
+        "slow_call_timeout_ms": 60000,
+        "slow_fetchmany_size": 5000,
+        "tcp_connect_timeout": 10,
+        "retry_count": 1,
+        "retry_delay": 1.0,
+    }
+
+    sem = MagicMock()
+    sem.acquire.return_value = True
+    mock_sem_fn.return_value = sem
+
+    cursor = MagicMock()
+    cursor.description = [("COL_A",), ("COL_B",)]
+    cursor.fetchall.return_value = [("v1", "v2")]
+
+    conn = MagicMock()
+    conn.cursor.return_value = cursor
+
+    engine = MagicMock()
+    engine.raw_connection.return_value = conn
+    mock_get_slow_engine.return_value = engine
+
+    df = db.read_sql_df_slow("SELECT 1", {"p0": "x"})
+
+    assert list(df.columns) == ["COL_A", "COL_B"]
+    assert len(df) == 1
+    mock_get_slow_engine.assert_called_once()
+    mock_oracledb.connect.assert_not_called()
+    conn.close.assert_called_once()
+    sem.release.assert_called_once()
+
+
+@patch.object(db, "oracledb")
+@patch.object(db, "get_slow_engine")
+@patch.object(db, "_get_slow_query_semaphore")
+@patch.object(db, "get_db_runtime_config")
+def test_read_sql_df_slow_iter_uses_slow_pool_when_enabled(
+    mock_runtime,
+    mock_sem_fn,
+    mock_get_slow_engine,
+    mock_oracledb,
+):
+    """Slow iterator query should checkout connection from isolated slow pool."""
+    mock_runtime.return_value = {
+        "slow_pool_enabled": True,
+        "slow_call_timeout_ms": 60000,
+        "slow_fetchmany_size": 2,
+        "tcp_connect_timeout": 10,
+        "retry_count": 1,
+        "retry_delay": 1.0,
+    }
+
+    sem = MagicMock()
+    sem.acquire.return_value = True
+    mock_sem_fn.return_value = sem
+
+    cursor = MagicMock()
+    cursor.description = [("COL_A",), ("COL_B",)]
+    cursor.fetchmany.side_effect = [
+        [("r1a", "r1b")],
+        [],
+    ]
+
+    conn = MagicMock()
+    conn.cursor.return_value = cursor
+
+    engine = MagicMock()
+    engine.raw_connection.return_value = conn
+    mock_get_slow_engine.return_value = engine
+
+    batches = list(db.read_sql_df_slow_iter("SELECT 1", {"p0": "x"}, batch_size=2))
+
+    assert batches == [(["COL_A", "COL_B"], [("r1a", "r1b")])]
+    mock_get_slow_engine.assert_called_once()
+    mock_oracledb.connect.assert_not_called()
+    conn.close.assert_called_once()
+    sem.release.assert_called_once()
+