Large transactions could run out of heap space. Fixed.

h2/src/docsrc/html/changelog.html

@@ -18,7 +18,9 @@ Change Log
 <h1>Change Log</h1>
 
 <h2>Next Version (unreleased)</h2>
-<ul><li>Creating a database was delayed about 2 seconds if the directory didn't exist.
+<ul><li>Large transactions could run out of heap space. Fixed.
+</li><li>The default setting for the system property h2.webMaxValueLength is now 100000 (it was 10000 before).
+</li><li>Creating a database was delayed about 2 seconds if the directory didn't exist.
 </li></ul>
 
 <h2>Version 1.2.129 (2010-02-19)</h2>
@@ -28,6 +30,9 @@ Change Log
 </li><li>MVCC: creating a table with an incorrect constraint could cause strange errors.
 </li><li>Hash indexes now are only used for single column indexes.
 </li><li>The cache types WEAK_* and TQ are no longer supported.
+    A weak reference cache never frees up memory so it's the same as
+    having a very large cache size. The TQ cache was not included in the
+    jar file since a longer time, and was not tested.
 </li><li>The file system abstraction no longer throws SQL exceptions.
 </li><li>DatabaseEventListener.diskSpaceIsLow has changed.
 </li><li>The CompressTool no longer throw as SQL exceptions. Instead, it throws runtime exceptions.
@@ -52,7 +57,10 @@ Change Log
 </li><li>The following system properties are no longer supported:
     h2.overflowExceptions, h2.optimizeDropDependencies, h2.optimizeGroupSorted,
     h2.optimizeMinMax, h2.optimizeNot, h2.optimizeIn, h2.optimizeInJoin, h2.reuseSpace*.
-</li><li>The setting LOG has currently no effect.
+    Most of then were there fore a long time, but always with the same value. 
+    There was no unit test with the other value. So changing them was potentially dangerous 
+    (not a lot, but still).
+</li><li>The setting LOG has currently no effect (it only had an effect when the page store was disabled).
 </li><li>Disabling the page store is no longer supported. The old storage mechanism
     has been removed, shrinking the jar file size by almost 10%.
 </li><li>The translated resources are now stored in UTF-8 format.

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

@@ -450,18 +450,19 @@ public class Session extends SessionWithState implements SessionFactory {
             database.commit(this);
         }
         if (undoLog.size() > 0) {
-            // commit the rows, even when not using MVCC
-            // see also TableData.addRow
-            ArrayList<Row> rows = New.arrayList();
-            synchronized (database) {
-                while (undoLog.size() > 0) {
-                    UndoLogRecord entry = undoLog.getLast();
-                    entry.commit();
-                    rows.add(entry.getRow());
-                    undoLog.removeLast(false);
-                }
-                for (Row r : rows) {
-                    r.commit();
+            // commit the rows when using MVCC
+            if (database.isMultiVersion()) {
+                ArrayList<Row> rows = New.arrayList();
+                synchronized (database) {
+                    while (undoLog.size() > 0) {
+                        UndoLogRecord entry = undoLog.getLast();
+                        entry.commit();
+                        rows.add(entry.getRow());
+                        undoLog.removeLast(false);
+                    }
+                    for (Row r : rows) {
+                        r.commit();
+                    }
                 }
             }
             undoLog.clear();

h2/src/main/org/h2/result/Row.java

@@ -25,7 +25,11 @@ public class Row implements SearchRow {
 
     public Row(Value[] data, int memory) {
         this.data = data;
-        this.memory = memory;
+        if (memory != MEMORY_CALCULATE) {
+            this.memory = 16 + memory * 4;
+        } else {
+            this.memory = MEMORY_CALCULATE;
+        }
     }
 
     public void setKeyAndVersion(SearchRow row) {
@@ -81,7 +85,7 @@ public class Row implements SearchRow {
 
     public int getMemorySize() {
         if (memory != MEMORY_CALCULATE) {
-            return 16 + memory * 4;
+            return memory;
         }
         int m = 8;
         for (int i = 0; data != null && i < data.length; i++) {

h2/src/main/org/h2/table/TableData.java

@@ -110,11 +110,9 @@ public class TableData extends Table {
     public void addRow(Session session, Row row) {
         int i = 0;
         lastModificationId = database.getNextModificationDataId();
-        // even when not using MVCC
-        // set the session, to ensure the row is kept in the cache
-        // until the transaction is committed or rolled back
-        // otherwise the row is not found when doing insert-delete-rollback
-        row.setSessionId(session.getId());
+        if (database.isMultiVersion()) {
+            row.setSessionId(session.getId());
+        }
         try {
             for (; i < indexes.size(); i++) {
                 Index index = indexes.get(i);