Experimental page store.

h2/src/main/org/h2/index/PageBtree.java

@@ -56,6 +56,11 @@ abstract class PageBtree extends Record {
      */
     protected int start;
 
+    /**
+     * If the page was already written to the buffer.
+     */
+    protected boolean written;
+
     PageBtree(PageBtreeIndex index, int pageId, int parentPageId, DataPage data) {
         this.index = index;
         this.parentPageId = parentPageId;
@@ -82,23 +87,36 @@ abstract class PageBtree extends Record {
      *
      * @param compare the row
      * @param bigger if looking for a larger row
+     * @param add if the row should be added (check for duplicate keys)
      * @return the index of the found row
      */
-    int find(SearchRow compare, boolean bigger) throws SQLException {
+    int find(SearchRow compare, boolean bigger, boolean add) throws SQLException {
         if (compare == null) {
             return 0;
         }
         int l = 0, r = entryCount;
+        int comp = 1;
         while (l < r) {
             int i = (l + r) >>> 1;
             SearchRow row = (SearchRow) getRow(i);
-            int comp = index.compareRows(row, compare);
+            comp = index.compareRows(row, compare);
+            if (comp == 0 && add) {
+                if (index.indexType.getUnique()) {
+                    if (!index.containsNullAndAllowMultipleNull(compare)) {
+                        throw index.getDuplicateKeyException();
+                    }
+                }
+                comp = index.compareKeys(row, compare);
+            }
             if (comp > 0 || (!bigger && comp == 0)) {
                 r = i;
             } else {
                 l = i + 1;
             }
         }
+        if (bigger && comp < 0) {
+            l++;
+        }
         return l;
     }
 

h2/src/main/org/h2/index/PageBtreeCursor.java

@@ -68,9 +68,9 @@ public class PageBtreeCursor implements Cursor {
             }
         }
         currentSearchRow = current.getRow(i);
+        currentRow = null;
         if (last != null && index.compareRows(currentSearchRow, last) > 0) {
             currentSearchRow = null;
-            currentRow = null;
             return false;
         }
         i++;

h2/src/main/org/h2/index/PageBtreeIndex.java

@@ -38,7 +38,7 @@ public class PageBtreeIndex extends BaseIndex {
             IndexType indexType, int headPos) throws SQLException {
         initBaseIndex(table, id, indexName, columns, indexType);
         int test;
-        // trace.setLevel(TraceSystem.DEBUG);
+// trace.setLevel(TraceSystem.DEBUG);
         if (database.isMultiVersion()) {
             int todoMvcc;
         }

h2/src/main/org/h2/index/PageBtreeLeaf.java

@@ -9,7 +9,6 @@ package org.h2.index;
 import java.sql.SQLException;
 import org.h2.constant.ErrorCode;
 import org.h2.message.Message;
-import org.h2.result.Row;
 import org.h2.result.SearchRow;
 import org.h2.store.DataPage;
 import org.h2.store.PageStore;
@@ -31,8 +30,6 @@ class PageBtreeLeaf extends PageBtree {
     private static final int KEY_OFFSET_PAIR_LENGTH = 6;
     private static final int KEY_OFFSET_PAIR_START = 11;
 
-    private boolean written;
-
     PageBtreeLeaf(PageBtreeIndex index, int pageId, int parentPageId, DataPage data) {
         super(index, pageId, parentPageId, data);
         start = KEY_OFFSET_PAIR_START;
@@ -66,13 +63,12 @@ class PageBtreeLeaf extends PageBtree {
     int addRow(SearchRow row) throws SQLException {
         int rowLength = index.getRowSize(data, row);
         int pageSize = index.getPageStore().getPageSize();
-        // TODO currently the order is important
-        // TODO and can only add at the end
         int last = entryCount == 0 ? pageSize : offsets[entryCount - 1];
         if (entryCount > 0 && last - rowLength < start + KEY_OFFSET_PAIR_LENGTH) {
             int todoSplitAtLastInsertionPoint;
             return (entryCount / 2) + 1;
         }
+        written = false;
         int offset = last - rowLength;
         int[] newOffsets = new int[entryCount + 1];
         SearchRow[] newRows = new SearchRow[entryCount + 1];
@@ -80,11 +76,14 @@ class PageBtreeLeaf extends PageBtree {
         if (entryCount == 0) {
             x = 0;
         } else {
-            x = find(row, false);
+            x = find(row, false, true);
             System.arraycopy(offsets, 0, newOffsets, 0, x);
             System.arraycopy(rows, 0, newRows, 0, x);
             if (x < entryCount) {
-                System.arraycopy(offsets, x, newOffsets, x + 1, entryCount - x);
+                for (int j = x; j < entryCount; j++) {
+                    newOffsets[j + 1] = offsets[j] - rowLength;
+                }
+                offset = (x == 0 ? pageSize : offsets[x - 1]) - rowLength;
                 System.arraycopy(rows, x, newRows, x + 1, entryCount - x);
             }
         }
@@ -111,14 +110,20 @@ class PageBtreeLeaf extends PageBtree {
 
     private void removeRow(int i) throws SQLException {
         entryCount--;
+        written = false;
         if (entryCount <= 0) {
             Message.throwInternalError();
         }
         int[] newOffsets = new int[entryCount];
-        Row[] newRows = new Row[entryCount];
+        SearchRow[] newRows = new SearchRow[entryCount];
         System.arraycopy(offsets, 0, newOffsets, 0, i);
         System.arraycopy(rows, 0, newRows, 0, i);
-        System.arraycopy(offsets, i + 1, newOffsets, i, entryCount - i);
+
+        int startNext = i > 0 ? offsets[i - 1] : index.getPageStore().getPageSize();
+        int rowLength = startNext - offsets[i];
+        for (int j = i; j < entryCount; j++) {
+            newOffsets[j] = offsets[j + 1] + rowLength;
+        }
         System.arraycopy(rows, i + 1, newRows, i, entryCount - i);
         start -= KEY_OFFSET_PAIR_LENGTH;
         offsets = newOffsets;
@@ -144,7 +149,7 @@ class PageBtreeLeaf extends PageBtree {
     }
 
     boolean remove(SearchRow row) throws SQLException {
-        int at = find(row, false);
+        int at = find(row, false, false);
         if (index.compareRows(row, getRow(at)) != 0) {
             throw Message.getSQLException(ErrorCode.ROW_NOT_FOUND_WHEN_DELETING_1, index.getSQL() + ": " + row);
         }
@@ -205,7 +210,7 @@ class PageBtreeLeaf extends PageBtree {
     }
 
     void find(PageBtreeCursor cursor, SearchRow first, boolean bigger) throws SQLException {
-        int i = find(first, bigger);
+        int i = find(first, bigger, false);
         if (i > entryCount) {
             if (parentPageId == Page.ROOT) {
                 return;

h2/src/main/org/h2/index/PageBtreeNode.java

@@ -38,6 +38,7 @@ class PageBtreeNode extends PageBtree {
 
     PageBtreeNode(PageBtreeIndex index, int pageId, int parentPageId, DataPage data) {
         super(index, pageId, parentPageId, data);
+        start = CHILD_OFFSET_PAIR_START;
     }
 
     void read() {
@@ -53,6 +54,7 @@ class PageBtreeNode extends PageBtree {
             offsets[i] = data.readInt();
         }
         check();
+        start = data.length();
     }
 
     /**
@@ -81,14 +83,18 @@ class PageBtreeNode extends PageBtree {
             System.arraycopy(offsets, 0, newOffsets, 0, x);
             System.arraycopy(rows, 0, newRows, 0, x);
             if (x < entryCount) {
-                System.arraycopy(offsets, x, newOffsets, x + 1, entryCount - x);
+                for (int j = x; j < entryCount; j++) {
+                    newOffsets[j + 1] = offsets[j] - rowLength;
+                }
+                offset = (x == 0 ? pageSize : offsets[x - 1]) - rowLength;
                 System.arraycopy(rows, x, newRows, x + 1, entryCount - x);
-                System.arraycopy(childPageIds, x, newChildPageIds, x + 1, entryCount - x + 1);
+                System.arraycopy(childPageIds, x + 1, newChildPageIds, x + 2, entryCount - x);
             }
         }
         newOffsets[x] = offset;
         newRows[x] = row;
         newChildPageIds[x + 1] = childPageId;
+        start += CHILD_OFFSET_PAIR_LENGTH;
         offsets = newOffsets;
         rows = newRows;
         childPageIds = newChildPageIds;
@@ -98,7 +104,7 @@ class PageBtreeNode extends PageBtree {
 
     int addRow(SearchRow row) throws SQLException {
         while (true) {
-            int x = find(row, false);
+            int x = find(row, false, true);
             PageBtree page = index.getPage(childPageIds[x]);
             int splitPoint = page.addRow(row);
             if (splitPoint == 0) {
@@ -116,6 +122,7 @@ class PageBtreeNode extends PageBtree {
             index.getPageStore().updateRecord(this, true, data);
         }
         updateRowCount(1);
+        written = false;
         return 0;
     }
 
@@ -171,7 +178,7 @@ class PageBtreeNode extends PageBtree {
     }
 
     void find(PageBtreeCursor cursor, SearchRow first, boolean bigger) throws SQLException {
-        int i = find(first, bigger);
+        int i = find(first, bigger, false);
         if (i > entryCount) {
             if (parentPageId == Page.ROOT) {
                 return;
@@ -190,7 +197,7 @@ class PageBtreeNode extends PageBtree {
     }
 
     boolean remove(SearchRow row) throws SQLException {
-        int at = find(row, false);
+        int at = find(row, false, false);
         // merge is not implemented to allow concurrent usage of btrees
         // TODO maybe implement merge
         PageBtree page = index.getPage(childPageIds[at]);
@@ -206,6 +213,7 @@ class PageBtreeNode extends PageBtree {
             // no more children - this page is empty as well
             return true;
         }
+        written = false;
         removeChild(at);
         index.getPageStore().updateRecord(this, true, data);
         return false;
@@ -245,6 +253,18 @@ class PageBtreeNode extends PageBtree {
 
     public void write(DataPage buff) throws SQLException {
         check();
+        write();
+        index.getPageStore().writePage(getPos(), data);
+    }
+
+    private void write() throws SQLException {
+        if (written) {
+            return;
+        }
+        // make sure rows are read
+        for (int i = 0; i < entryCount; i++) {
+            getRow(i);
+        }
         data.reset();
         data.writeInt(parentPageId);
         data.writeByte((byte) Page.TYPE_BTREE_NODE);
@@ -255,28 +275,37 @@ class PageBtreeNode extends PageBtree {
             data.writeInt(childPageIds[i]);
             data.writeInt(offsets[i]);
         }
-        index.getPageStore().writePage(getPos(), data);
+        for (int i = 0; i < entryCount; i++) {
+            index.writeRow(data, offsets[i], rows[i]);
+        }
+        written = true;
     }
 
     private void removeChild(int i) throws SQLException {
         entryCount--;
+        written = false;
         if (entryCount < 0) {
             Message.throwInternalError();
         }
+        SearchRow[] newRows = new SearchRow[entryCount];
         int[] newOffsets = new int[entryCount];
-        SearchRow[] newRows = new SearchRow[entryCount + 1];
         int[] newChildPageIds = new int[entryCount + 1];
         System.arraycopy(offsets, 0, newOffsets, 0, Math.min(entryCount, i));
         System.arraycopy(rows, 0, newRows, 0, Math.min(entryCount, i));
         System.arraycopy(childPageIds, 0, newChildPageIds, 0, i);
         if (entryCount > i) {
-            System.arraycopy(offsets, i + 1, newOffsets, i, entryCount - i);
             System.arraycopy(rows, i + 1, newRows, i, entryCount - i);
+            int startNext = i > 0 ? offsets[i - 1] : index.getPageStore().getPageSize();
+            int rowLength = startNext - offsets[i];
+            for (int j = i; j < entryCount; j++) {
+                newOffsets[j] = offsets[j + 1] + rowLength;
+            }
         }
         System.arraycopy(childPageIds, i + 1, newChildPageIds, i, entryCount - i + 1);
         offsets = newOffsets;
         rows = newRows;
         childPageIds = newChildPageIds;
+        start -= CHILD_OFFSET_PAIR_LENGTH;
     }
 
     /**
@@ -286,7 +315,7 @@ class PageBtreeNode extends PageBtree {
      * @param row the current row
      */
     void nextPage(PageBtreeCursor cursor, SearchRow row) throws SQLException {
-        int i = find(row, true);
+        int i = find(row, true, false);
         if (i > entryCount) {
             if (parentPageId == Page.ROOT) {
                 cursor.setCurrent(null, 0);

h2/src/main/org/h2/index/PageDataLeaf.java

@@ -6,7 +6,6 @@
  */
 package org.h2.index;
 import java.sql.SQLException;
-import java.util.Arrays;
 
 import org.h2.constant.ErrorCode;
 import org.h2.engine.Session;
@@ -106,6 +105,7 @@ class PageDataLeaf extends PageData {
         if (entryCount == 0) {
             x = 0;
         } else {
+            readAllRows();
             x = find(row.getPos());
             System.arraycopy(offsets, 0, newOffsets, 0, x);
             System.arraycopy(keys, 0, newKeys, 0, x);
@@ -118,6 +118,7 @@ class PageDataLeaf extends PageData {
                 System.arraycopy(rows, x, newRows, x + 1, entryCount - x);
             }
         }
+        written = false;
         last = x == 0 ? pageSize : offsets[x - 1];
         offset = last - rowLength;
         entryCount++;
@@ -168,6 +169,8 @@ class PageDataLeaf extends PageData {
     }
 
     private void removeRow(int i) throws SQLException {
+        written = false;
+        readAllRows();
         entryCount--;
         if (entryCount <= 0) {
             Message.throwInternalError();
@@ -178,8 +181,8 @@ class PageDataLeaf extends PageData {
         System.arraycopy(offsets, 0, newOffsets, 0, i);
         System.arraycopy(keys, 0, newKeys, 0, i);
         System.arraycopy(rows, 0, newRows, 0, i);
-        int startNext = i < entryCount - 1 ? offsets[i + 1] : index.getPageStore().getPageSize();
-        int rowLength = offsets[i] - startNext;
+        int startNext = i > 0 ? offsets[i - 1] : index.getPageStore().getPageSize();
+        int rowLength = startNext - offsets[i];
         for (int j = i; j < entryCount; j++) {
             newOffsets[j] = offsets[j + 1] + rowLength;
         }
@@ -202,6 +205,10 @@ class PageDataLeaf extends PageData {
      * @return the row
      */
     Row getRowAt(int at) throws SQLException {
+int test;
+if (at >= rows.length) {
+    System.out.println("stop");
+}
         Row r = rows[at];
         if (r == null) {
             if (firstOverflowPageId != 0) {
@@ -320,14 +327,17 @@ class PageDataLeaf extends PageData {
         return index.getPageStore();
     }
 
+    private void readAllRows() throws SQLException {
+        for (int i = 0; i < entryCount; i++) {
+            getRowAt(i);
+        }
+    }
+
     private void write() throws SQLException {
         if (written) {
             return;
         }
-        // make sure rows are read
-        for (int i = 0; i < entryCount; i++) {
-            getRowAt(i);
-        }
+        readAllRows();
         data.reset();
         data.writeInt(parentPageId);
         int type;
@@ -342,9 +352,6 @@ class PageDataLeaf extends PageData {
         if (firstOverflowPageId != 0) {
             data.writeInt(firstOverflowPageId);
         }
-        if (getPos() == 1) {
-            System.out.println("pause");
-        }
         for (int i = 0; i < entryCount; i++) {
             data.writeInt(keys[i]);
             data.writeShortInt(offsets[i]);

h2/src/main/org/h2/index/PageScanIndex.java

@@ -40,7 +40,7 @@ public class PageScanIndex extends BaseIndex implements RowIndex {
     public PageScanIndex(TableData table, int id, IndexColumn[] columns, IndexType indexType, int headPos) throws SQLException {
         initBaseIndex(table, id, table.getName() + "_TABLE_SCAN", columns, indexType);
         int test;
-        trace.setLevel(TraceSystem.DEBUG);
+// trace.setLevel(TraceSystem.DEBUG);
         if (database.isMultiVersion()) {
             int todoMvcc;
         }
@@ -89,10 +89,6 @@ public class PageScanIndex extends BaseIndex implements RowIndex {
             lastKey = Math.max(lastKey, row.getPos() + 1);
         }
         if (trace.isDebugEnabled()) {
-            int test;
-            if (table.getId() == -1) {
-                System.out.println("pause");
-            }
             trace.debug("add table:" + table.getId() + " " + row);
         }
         if (tableData.getContainsLargeObject()) {
@@ -197,8 +193,8 @@ public class PageScanIndex extends BaseIndex implements RowIndex {
     public void remove(Session session, Row row) throws SQLException {
         if (trace.isDebugEnabled()) {
             trace.debug("remove " + row.getPos());
-            if (table.getId() == -1) {
-                System.out.println("pause");
+            if (table.getId() == 0) {
+                System.out.println("table 0 remove");
             }
         }
         if (tableData.getContainsLargeObject()) {

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

@@ -11,7 +11,6 @@ import java.io.OutputStream;
 import java.sql.SQLException;
 import java.util.HashMap;
 import java.util.Iterator;
-import java.util.WeakHashMap;
 import org.h2.constant.ErrorCode;
 import org.h2.engine.Database;
 import org.h2.engine.Session;
@@ -37,8 +36,8 @@ import org.h2.util.CacheWriter;
 import org.h2.util.FileUtils;
 import org.h2.util.ObjectArray;
 import org.h2.util.ObjectUtils;
-import org.h2.util.SoftHashMap;
 import org.h2.util.StringUtils;
+import org.h2.value.CompareMode;
 import org.h2.value.Value;
 import org.h2.value.ValueInt;
 import org.h2.value.ValueString;
@@ -61,9 +60,13 @@ import org.h2.value.ValueString;
  */
 public class PageStore implements CacheWriter {
 
+    // TODO PageDataLeaf and Node: support random delete/add
+
+    // TODO PageStore.openMetaIndex (add collation for indexes,
+    // desc columns support)
+
     // TODO btree index with fixed size values doesn't need offset and so on
     // TODO log block allocation
-    // TODO use free-space bitmap
     // TODO block compression: maybe http://en.wikipedia.org/wiki/LZJB
     // with RLE, specially for 0s.
     // TODO test that setPageId updates parent, overflow parent
@@ -91,6 +94,7 @@ public class PageStore implements CacheWriter {
     // TODO split files (1 GB max size)
     // TODO add a setting (that can be changed at runtime) to call fsync
     // and delay on each commit
+    // TODO var int: see google protocol buffers
 
     /**
      * The smallest possible page size.
@@ -174,7 +178,7 @@ public class PageStore implements CacheWriter {
         this.database = database;
         trace = database.getTrace(Trace.PAGE_STORE);
         int test;
-trace.setLevel(TraceSystem.DEBUG);
+// trace.setLevel(TraceSystem.DEBUG);
         this.cacheSize = cacheSizeDefault;
         String cacheType = database.getCacheType();
         this.cache = CacheLRU.getCache(this, cacheType, cacheSize);
@@ -257,7 +261,7 @@ trace.setLevel(TraceSystem.DEBUG);
      */
     public void checkpoint() throws SQLException {
         trace.debug("checkpoint");
-        if (getLog() == null) {
+        if (getLog() == null || database.isReadOnly()) {
             // the file was never fully opened
             return;
         }
@@ -270,6 +274,8 @@ trace.setLevel(TraceSystem.DEBUG);
                 writeBack(rec);
             }
             int todoFlushBeforeReopen;
+            // switch twice so there are no redo entries
+            switchLogIfPossible();
             switchLogIfPossible();
             int todoWriteDeletedPages;
         }
@@ -280,6 +286,9 @@ trace.setLevel(TraceSystem.DEBUG);
 
     private void switchLogIfPossible() throws SQLException {
         trace.debug("switchLogIfPossible");
+        if (database.isReadOnly()) {
+            return;
+        }
         int id = getLog().getId();
         getLog().close();
         activeLog = (activeLog + 1) % LOG_COUNT;
@@ -409,10 +418,6 @@ trace.setLevel(TraceSystem.DEBUG);
         synchronized (database) {
             Record record = (Record) obj;
             if (trace.isDebugEnabled()) {
-                int test;
-                if (record.getPos() == 1) {
-                    System.out.println("pause");
-                }
                 trace.debug("writeBack " + record);
             }
             int todoRemoveParameter;
@@ -432,10 +437,6 @@ trace.setLevel(TraceSystem.DEBUG);
         synchronized (database) {
             if (trace.isDebugEnabled()) {
                 if (!record.isChanged()) {
-                    int test;
-                    if(record.getPos() == 1) {
-                        System.out.println("pause");
-                    }
                     trace.debug("updateRecord " + record.toString());
                 }
             }
@@ -817,6 +818,7 @@ trace.setLevel(TraceSystem.DEBUG);
         cols.add(new Column("PARENT", Value.INT));
         cols.add(new Column("HEAD", Value.INT));
         cols.add(new Column("COLUMNS", Value.STRING));
+//        new CompareMode()
         metaSchema = new Schema(database, 0, "", null, true);
         int headPos = metaTableRootPageId;
         metaTable = new TableData(metaSchema, "PAGE_INDEX",
@@ -906,6 +908,9 @@ trace.setLevel(TraceSystem.DEBUG);
         row.setValue(4, ValueString.get(columnList));
         row.setPos(id + 1);
         metaIndex.add(database.getSystemSession(), row);
+
+int assertion;
+metaIndex.getRow(database.getSystemSession(), row.getPos());
     }
 
     /**

h2/src/test/org/h2/test/unit/TestPageStore.java

@@ -13,8 +13,14 @@ import java.io.FileInputStream;
 import java.io.FileOutputStream;
 import java.io.InputStream;
 import java.io.OutputStream;
+import java.sql.Connection;
+import java.sql.ResultSet;
 import java.sql.SQLException;
+import java.sql.Statement;
+import java.util.Iterator;
 import java.util.Random;
+import java.util.Set;
+import java.util.TreeSet;
 import org.h2.constant.SysProperties;
 import org.h2.engine.ConnectionInfo;
 import org.h2.engine.Database;
@@ -58,13 +64,87 @@ public class TestPageStore extends TestBase {
     }
 
     public void test() throws Exception {
+        testFuzzOperations();
         testScanIndex();
-        testBtreeIndex();
+        // testBtreeIndex();
         // testAllocateFree();
         // testStreamFuzz();
         // testStreamPerformance(false, 1000);
-        // testPerformance(true, 1000000);
-        // testPerformance(false, 1000000);
+    }
+
+    private void testFuzzOperations() throws SQLException {
+        int best = Integer.MAX_VALUE;
+        for (int i = 0; i < 10; i++) {
+            int x = testFuzzOperationsSeed(i, 10);
+            if (x >= 0 && x < best) {
+                best = x;
+                fail("op:" + x + " seed:" + i);
+            }
+        }
+    }
+
+    private int testFuzzOperationsSeed(int seed, int len) throws SQLException {
+        deleteDb("test");
+        Connection conn = getConnection("test");
+        Statement stat = conn.createStatement();
+        log("DROP TABLE IF EXISTS TEST;");
+        stat.execute("DROP TABLE IF EXISTS TEST");
+        log("CREATE TABLE TEST(ID INT PRIMARY KEY, NAME VARCHAR DEFAULT 'Hello World');");
+        stat.execute("CREATE TABLE TEST(ID INT PRIMARY KEY, NAME VARCHAR DEFAULT 'Hello World')");
+        Set rows = new TreeSet();
+        Random random = new Random(seed);
+        for (int i = 0; i < len; i++) {
+            int op = random.nextInt(3);
+            Integer x = new Integer(random.nextInt(100));
+            switch(op) {
+            case 0:
+                if (!rows.contains(x)) {
+                    log("insert into test(id) values(" + x + ");");
+                    stat.execute("INSERT INTO TEST(ID) VALUES("+ x + ");");
+                    rows.add(x);
+                }
+                break;
+            case 1:
+                if (rows.contains(x)) {
+                    log("delete from test where id=" + x + ";");
+                    stat.execute("DELETE FROM TEST WHERE ID=" + x);
+                    rows.remove(x);
+                }
+                break;
+            case 2:
+                conn.close();
+                conn = getConnection("test");
+                stat = conn.createStatement();
+                ResultSet rs = stat.executeQuery("SELECT * FROM TEST ORDER BY ID");
+                log("--reconnect");
+                for (Iterator it = rows.iterator(); it.hasNext();) {
+                    int test = ((Integer) it.next()).intValue();
+                    if (!rs.next()) {
+                        log("error: expected next");
+                        conn.close();
+                        return i;
+                    }
+                    int y = rs.getInt(1);
+                    // System.out.println(" " + x);
+                    if (y != test) {
+                        log("error: " + y + " <> " + test);
+                        conn.close();
+                        return i;
+                    }
+                }
+                if (rs.next()) {
+                    log("error: unexpected next");
+                    conn.close();
+                    return i;
+                }
+            }
+        }
+        conn.close();
+        return -1;
+    }
+
+    private void log(String m) {
+        trace("   " + m);
     }
 
     private void testBtreeIndex() throws SQLException {