Merge pull request #1078 from grandinj/1023_mvcc

#1023: MVCC and existing page store file

h2/src/docsrc/html/changelog.html

@@ -21,6 +21,8 @@ Change Log
 
 <h2>Next Version (unreleased)</h2>
 <ul>
+<li>Issue #1023: MVCC and existing page store file 
+</li>
 <li>Issue #1003: Decrypting database with incorrect password renders the database corrupt 
 </li>
 <li>Issue #873: No error when `=` in equal condition when column is not of array type 

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

@@ -166,6 +166,7 @@ public class Database implements DataHandler {
     private final String cacheType;
     private final String accessModeData;
     private boolean referentialIntegrity = true;
+    /** ie. the MVCC setting */
     private boolean multiVersion;
     private DatabaseCloser closeOnExit;
     private Mode mode = Mode.getRegular();
@@ -279,13 +280,13 @@ public class Database implements DataHandler {
                 TraceSystem.DEFAULT_TRACE_LEVEL_SYSTEM_OUT);
         this.cacheType = StringUtils.toUpperEnglish(
                 ci.removeProperty("CACHE_TYPE", Constants.CACHE_TYPE_DEFAULT));
-        openDatabase(traceLevelFile, traceLevelSystemOut, closeAtVmShutdown);
+        openDatabase(traceLevelFile, traceLevelSystemOut, closeAtVmShutdown, ci);
     }
 
     private void openDatabase(int traceLevelFile, int traceLevelSystemOut,
-            boolean closeAtVmShutdown) {
+            boolean closeAtVmShutdown, ConnectionInfo ci) {
         try {
-            open(traceLevelFile, traceLevelSystemOut);
+            open(traceLevelFile, traceLevelSystemOut, ci);
             if (closeAtVmShutdown) {
                 try {
                     closeOnExit = new DatabaseCloser(this, 0, true);
@@ -608,7 +609,7 @@ public class Database implements DataHandler {
         return dbSettings.databaseToUpper ? StringUtils.toUpperEnglish(n) : n;
     }
 
-    private synchronized void open(int traceLevelFile, int traceLevelSystemOut) {
+    private synchronized void open(int traceLevelFile, int traceLevelSystemOut, ConnectionInfo ci) {
         if (persistent) {
             String dataFileName = databaseName + Constants.SUFFIX_OLD_DATABASE_FILE;
             boolean existsData = FileUtils.exists(dataFileName);
@@ -631,6 +632,9 @@ public class Database implements DataHandler {
             }
             if (existsPage && !existsMv) {
                 dbSettings.mvStore = false;
+                // Need to re-init this because the first time we do it we don't
+                // know if we have an mvstore or a pagestore.
+                multiVersion = ci.getProperty("MVCC", false);
             }
             if (readOnly) {
                 if (traceLevelFile >= TraceSystem.DEBUG) {

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

@@ -6,7 +6,6 @@
 package org.h2.engine;
 
 import java.util.HashMap;
-
 import org.h2.message.DbException;
 import org.h2.util.Utils;