Issue 581: When running in LOCK_MODE=0,

    JdbcDatabaseMetaData#supportsTransactionIsolationLevel(TRANSACTION_READ_UNCOMMITTED)
should return false

h2/src/docsrc/html/changelog.html

@@ -17,7 +17,9 @@ Change Log
 <h1>Change Log</h1>
 
 <h2>Next Version (unreleased)</h2>
-<ul><li>-
+<ul><li>Issue 581: When running in LOCK_MODE=0,
+        JdbcDatabaseMetaData#supportsTransactionIsolationLevel(TRANSACTION_READ_UNCOMMITTED)
+    should return false
 </li></ul>
 
 <h2>Version 1.4.182 Beta (2014-10-17)</h2>

h2/src/main/org/h2/engine/Database.java

@@ -2091,7 +2091,8 @@ public class Database implements DataHandler {
         case Constants.LOCK_MODE_OFF:
             if (multiThreaded) {
                 // currently the combination of LOCK_MODE=0 and MULTI_THREADED
-                // is not supported
+                // is not supported. also see code in
+                // JdbcDatabaseMetaData#supportsTransactionIsolationLevel(int)
                 throw DbException.get(
                         ErrorCode.UNSUPPORTED_SETTING_COMBINATION,
                         "LOCK_MODE=0 & MULTI_THREADED");

h2/src/main/org/h2/jdbc/JdbcDatabaseMetaData.java

@@ -2200,8 +2200,19 @@ public class JdbcDatabaseMetaData extends TraceObject implements
      * @return true
      */
     @Override
-    public boolean supportsTransactionIsolationLevel(int level) {
+    public boolean supportsTransactionIsolationLevel(int level) throws SQLException {
         debugCodeCall("supportsTransactionIsolationLevel");
+        if (level == Connection.TRANSACTION_READ_UNCOMMITTED) {
+            // currently the combination of LOCK_MODE=0 and MULTI_THREADED
+            // is not supported, also see code in Database#setLockMode(int)
+            PreparedStatement prep = conn.prepareAutoCloseStatement(
+                    "SELECT VALUE FROM INFORMATION_SCHEMA.SETTINGS WHERE NAME=?");
+            prep.setString(1, "MULTI_THREADED");
+            ResultSet rs = prep.executeQuery();
+            if (rs.next() && rs.getString(1).equals("1")) {
+                return false;
+            }
+        }
         return true;
     }
 

h2/src/test/org/h2/test/db/TestMultiThread.java

@@ -7,6 +7,7 @@ package org.h2.test.db;
 
 import java.io.StringReader;
 import java.sql.Connection;
+import java.sql.DatabaseMetaData;
 import java.sql.PreparedStatement;
 import java.sql.ResultSet;
 import java.sql.SQLException;
@@ -58,6 +59,7 @@ public class TestMultiThread extends TestBase implements Runnable {
         testConcurrentAlter();
         testConcurrentAnalyze();
         testConcurrentInsertUpdateSelect();
+        testMetadataWith();
     }
 
     private void testConcurrentLobAdd() throws Exception {
@@ -244,4 +246,15 @@ public class TestMultiThread extends TestBase implements Runnable {
         }
     }
 
+    private void testMetadataWith() throws Exception {
+        // currently the combination of LOCK_MODE=0 and MULTI_THREADED
+        // is not supported. also see code in
+        deleteDb("concurrentAnalyze");
+        final String url = getURL("concurrentAnalyze;MULTI_THREADED=1", true);
+        Connection conn = getConnection(url);
+        DatabaseMetaData dmd = conn.getMetaData();
+        assertFalse(dmd.supportsTransactionIsolationLevel(Connection.TRANSACTION_READ_UNCOMMITTED));
+        conn.close();
+        deleteDb("concurrentAnalyze");
+    }
 }