Docs

h2/src/docsrc/html/changelog.html

@@ -21,6 +21,11 @@ Change Log
 
 <h2>Next Version (unreleased)</h2>
 <ul>
+<li>MVStore CLOB and BLOB: An exception with the message "Block not found" could be thrown
+    when using the MVStore storage, when copying LOB objects
+    (for example due to "alter table" on a table with a LOB object),
+    and then re-opening the database.
+</li>
 <li>Fix for issue #171: Broken QueryStatisticsData duration data when trace level < TraceSystem.INFO
 </li>
 <li>Pull request #170: Added SET QUERY_STATISTICS_MAX_ENTRIES

h2/src/installer/release.txt

@@ -19,6 +19,7 @@ Check docs, versions and links in main, downloads, build numbers
 Check the PDF file size
 
 Upload to SourceForge
+Upload to ftp://h2database.com/javadoc
 Upload to ftp://h2database.com
 Upload to ftp://h2database.com/m2-repo
 Github: create a release

h2/src/main/org/h2/store/LobStorageMap.java

@@ -24,6 +24,7 @@ import org.h2.mvstore.StreamStore;
 import org.h2.mvstore.db.MVTableEngine.Store;
 import org.h2.util.IOUtils;
 import org.h2.util.New;
+import org.h2.util.StringUtils;
 import org.h2.value.Value;
 import org.h2.value.ValueLobDb;
 
@@ -101,19 +102,26 @@ public class LobStorageMap implements LobStorageInterface {
         if (dataMap.isEmpty()) {
             return;
         }
-        // search the last referenced block
-        // (a lob may not have any referenced blocks if data is kept inline,
-        // so we need to loop)
+        // search for the last block
+        // (in theory, only the latest lob can have unreferenced blocks,
+        // but the latest lob could by a copy of another one, and
+        // we don't know that, so we iterate over all lobs)
         long lastUsedKey = -1;
-        Long lobId = lobMap.lastKey();
-        while (lobId != null) {
-            Object[] v = lobMap.get(lobId);
+        for (Entry<Long, Object[]> e : lobMap.entrySet()) {
+            long lobId = e.getKey();
+            Object[] v = e.getValue();
             byte[] id = (byte[]) v[0];
-            lastUsedKey = streamStore.getMaxBlockKey(id);
-            if (lastUsedKey >= 0) {
-                break;
+            long max = streamStore.getMaxBlockKey(id);
+            // a lob may not have a referenced blocks if data is kept inline
+            if (max != -1 && max > lastUsedKey) {
+                lastUsedKey = max;
+                if (TRACE) {
+                    trace("lob " + lobId + " lastUsedKey=" + lastUsedKey);
                 }
-            lobId = lobMap.lowerKey(lobId);
+            }
+        }
+        if (TRACE) {
+            trace("lastUsedKey=" + lastUsedKey);
         }
         // delete all blocks that are newer
         while (true) {
@@ -121,6 +129,9 @@ public class LobStorageMap implements LobStorageInterface {
             if (last == null || last <= lastUsedKey) {
                 break;
             }
+            if (TRACE) {
+                trace("gc " + last);
+            }
             dataMap.remove(last);
         }
         // don't re-use block ids, except at the very end
@@ -349,10 +360,16 @@ public class LobStorageMap implements LobStorageInterface {
         if (value != null) {
             byte[] s2 = (byte[]) value[0];
             if (Arrays.equals(streamStoreId, s2)) {
+                if (TRACE) {
+                    trace("  stream still needed in lob " + value[1]);
+                }
                 hasMoreEntries = true;
             }
         }
         if (!hasMoreEntries) {
+            if (TRACE) {
+                trace("  remove stream " + StringUtils.convertBytesToHex(streamStoreId));
+            }
             streamStore.remove(streamStoreId);
         }
     }

h2/src/test/org/h2/test/store/TestMVTableEngine.java

@@ -50,6 +50,7 @@ public class TestMVTableEngine extends TestBase {
 
     @Override
     public void test() throws Exception {
+        testLobCopy();
         testLobReuse();
         testShutdownDuringLobCreation();
         testLobCreationThenShutdown();
@@ -87,6 +88,27 @@ public class TestMVTableEngine extends TestBase {
         testSimple();
     }
 
+    private void testLobCopy() throws Exception {
+        deleteDb(getTestName());
+        Connection conn = getConnection(getTestName());
+        Statement stat = conn.createStatement();
+        stat.execute("create table test(id int primary key, data clob)");
+        stat = conn.createStatement();
+        stat.execute("insert into test(id, data) values(2, space(300))");
+        stat.execute("insert into test(id, data) values(1, space(300))");
+        stat.execute("alter table test add column x int");
+        if (!config.memory) {
+            conn.close();
+            conn = getConnection(getTestName());
+        }
+        stat = conn.createStatement();
+        ResultSet rs = stat.executeQuery("select data from test");
+        while (rs.next()) {
+            rs.getString(1);
+        }
+        conn.close();
+    }
+
     private void testLobReuse() throws Exception {
         deleteDb(getTestName());
         Connection conn = getConnection(getTestName());