Use constants where possible.

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

@@ -431,11 +431,15 @@ public class Constants {
      */
     public static final String SUFFIX_LOCK_FILE = ".lock.db";
 
+    /**
+     * The file name suffix of a H2 version 1.1 database file.
+     */
+    public static final String SUFFIX_OLD_DATABASE_FILE = ".data.db";
+
     /**
      * The file name suffix of page files.
      */
     public static final String SUFFIX_PAGE_FILE = ".h2.db";
-
     /**
      * The file name suffix of a MVStore file.
      */

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

@@ -568,7 +568,7 @@ public class Database implements DataHandler {
 
     private synchronized void open(int traceLevelFile, int traceLevelSystemOut) {
         if (persistent) {
-            String dataFileName = databaseName + ".data.db";
+            String dataFileName = databaseName + Constants.SUFFIX_OLD_DATABASE_FILE;
             boolean existsData = FileUtils.exists(dataFileName);
             String pageFileName = databaseName + Constants.SUFFIX_PAGE_FILE;
             String mvFileName = databaseName + Constants.SUFFIX_MV_FILE;

h2/src/main/org/h2/upgrade/DbUpgrade.java

@@ -13,6 +13,7 @@ import java.sql.Statement;
 import java.util.Properties;
 import java.util.UUID;
 import org.h2.engine.ConnectionInfo;
+import org.h2.engine.Constants;
 import org.h2.jdbc.JdbcConnection;
 import org.h2.message.DbException;
 import org.h2.store.fs.FileUtils;
@@ -62,10 +63,10 @@ public class DbUpgrade {
             return null;
         }
         String name = ci.getName();
-        if (FileUtils.exists(name + ".h2.db")) {
+        if (FileUtils.exists(name + Constants.SUFFIX_PAGE_FILE)) {
             return null;
         }
-        if (!FileUtils.exists(name + ".data.db")) {
+        if (!FileUtils.exists(name + Constants.SUFFIX_OLD_DATABASE_FILE)) {
             return null;
         }
         if (ci.removeProperty("NO_UPGRADE", false)) {
@@ -110,7 +111,7 @@ public class DbUpgrade {
     private static void upgrade(ConnectionInfo ci, Properties info)
             throws SQLException {
         String name = ci.getName();
-        String data = name + ".data.db";
+        String data = name + Constants.SUFFIX_OLD_DATABASE_FILE;
         String index = name + ".index.db";
         String lobs = name + ".lobs.db";
         String backupData = data + ".backup";

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

@@ -5,11 +5,12 @@
  */
 package org.h2.test.db;
 
-import java.io.File;
 import java.sql.Connection;
 import java.sql.SQLException;
 import java.sql.Statement;
 
+import org.h2.engine.Constants;
+import org.h2.store.fs.FileUtils;
 import org.h2.test.TestBase;
 
 /**
@@ -32,24 +33,32 @@ public class TestSpaceReuse extends TestBase {
             return;
         }
         deleteDb("spaceReuse");
-        long first = 0, now = 0;
-        for (int i = 0; i < 10; i++) {
+        long max = 0, now = 0, min = Long.MAX_VALUE;
+        for (int i = 0; i < 20; i++) {
             Connection conn = getConnection("spaceReuse");
             Statement stat = conn.createStatement();
+            stat.execute("set retention_time 0");
             stat.execute("create table if not exists t(i int)");
             stat.execute("insert into t select x from system_range(1, 500)");
             conn.close();
             conn = getConnection("spaceReuse");
             conn.createStatement().execute("delete from t");
             conn.close();
-            now = new File(getBaseDir() + "/spaceReuse.data.db").length();
-            if (first == 0) {
-                first = now;
+            String fileName = getBaseDir() + "/spaceReuse";
+            if (Constants.VERSION_MINOR >= 4) {
+                fileName += Constants.SUFFIX_MV_FILE;
+            } else {
+                fileName += Constants.SUFFIX_PAGE_FILE;
+            }
+            now = FileUtils.size(fileName);
+            assertTrue(now > 0);
+            if (i < 10) {
+                max = Math.max(max, now);
+            } else {
+                min = Math.min(min, now);
             }
         }
-        if (now > first) {
-            fail("first: " + first + " now: " + now);
-        }
+        assertTrue("min: " + min + " max: " + max, min <= max);
         deleteDb("spaceReuse");
     }
 

h2/src/tools/org/h2/dev/util/Migrate.java

@@ -73,7 +73,7 @@ public class Migrate {
             }
             return;
         }
-        if (!file.getName().endsWith(".data.db")) {
+        if (!file.getName().endsWith(Constants.SUFFIX_OLD_DATABASE_FILE)) {
             return;
         }
         println("Migrating " + file.getName());
@@ -81,7 +81,7 @@ public class Migrate {
             download(OLD_H2_FILE.getAbsolutePath(), DOWNLOAD_URL, CHECKSUM);
         }
         String url = "jdbc:h2:" + file.getAbsolutePath();
-        url = url.substring(0, url.length() - ".data.db".length());
+        url = url.substring(0, url.length() - Constants.SUFFIX_OLD_DATABASE_FILE.length());
         exec(new String[] {
                 pathToJavaExe,
                 "-Xmx128m",