plan and tests

h2/src/main/org/h2/command/CommandContainer.java

@@ -7,6 +7,7 @@ package org.h2.command;
 
 import java.util.ArrayList;
 import org.h2.api.DatabaseEventListener;
+import org.h2.command.dml.Explain;
 import org.h2.command.dml.Query;
 import org.h2.expression.Parameter;
 import org.h2.expression.ParameterInterface;
@@ -47,8 +48,18 @@ public class CommandContainer extends Command {
 
     @Override
     public void prepareJoinBatch() {
-        if (session.isJoinBatchEnabled() && prepared.isQuery()) {
-            ((Query) prepared).prepareJoinBatch();
+        if (session.isJoinBatchEnabled()) {
+            prepareJoinBatch(prepared);
+        }
+    }
+
+    private static void prepareJoinBatch(Prepared prepared) {
+        if (prepared.isQuery()) {
+            if (prepared.getType() == CommandInterface.SELECT) {
+                ((Query) prepared).prepareJoinBatch();
+            } else if (prepared.getType() == CommandInterface.EXPLAIN) {
+                prepareJoinBatch(((Explain) prepared).getCommand());
+            }
         }
     }
 

h2/src/main/org/h2/command/ddl/AlterTableAddConstraint.java

@@ -294,6 +294,9 @@ public class AlterTableAddConstraint extends SchemaCommand {
     }
 
     private static Index getUniqueIndex(Table t, IndexColumn[] cols) {
+        if (t.getIndexes() == null) {
+            return null;
+        }
         for (Index idx : t.getIndexes()) {
             if (canUseUniqueIndex(idx, t, cols)) {
                 return idx;
@@ -303,6 +306,9 @@ public class AlterTableAddConstraint extends SchemaCommand {
     }
 
     private static Index getIndex(Table t, IndexColumn[] cols, boolean moreColumnOk) {
+        if (t.getIndexes() == null) {
+            return null;
+        }
         for (Index idx : t.getIndexes()) {
             if (canUseIndex(idx, t, cols, moreColumnOk)) {
                 return idx;

h2/src/main/org/h2/command/dml/Delete.java

@@ -132,7 +132,7 @@ public class Delete extends Prepared {
         }
         PlanItem item = tableFilter.getBestPlanItem(session, new TableFilter[]{tableFilter}, 0);
         tableFilter.setPlanItem(item);
-        tableFilter.prepare();
+        tableFilter.prepare(false);
     }
 
     @Override

h2/src/main/org/h2/command/dml/Explain.java

@@ -40,6 +40,10 @@ public class Explain extends Prepared {
         this.command = command;
     }
 
+    public Prepared getCommand() {
+        return command;
+    }
+
     @Override
     public void prepare() {
         command.prepare();

h2/src/main/org/h2/command/dml/NoOperation.java

@@ -24,11 +24,6 @@ public class NoOperation extends Prepared {
         return 0;
     }
 
-    @Override
-    public boolean isQuery() {
-        return false;
-    }
-
     @Override
     public boolean isTransactional() {
         return true;

h2/src/main/org/h2/command/dml/Select.java

@@ -1010,9 +1010,7 @@ public class Select extends Query {
 
         setEvaluatableRecursive(topTableFilter);
 
-        if (!parse) {
-            topTableFilter.prepare();
-        }
+        topTableFilter.prepare(parse);
         return planCost;
     }
 

h2/src/main/org/h2/command/dml/Update.java

@@ -189,7 +189,7 @@ public class Update extends Prepared {
         }
         PlanItem item = tableFilter.getBestPlanItem(session, new TableFilter[] {tableFilter}, 0);
         tableFilter.setPlanItem(item);
-        tableFilter.prepare();
+        tableFilter.prepare(false);
     }
 
     @Override

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

@@ -51,6 +51,13 @@ public interface IndexLookupBatch {
      */
     List<Future<Cursor>> find();
 
+    /**
+     * Get plan for EXPLAIN.
+     *
+     * @return plan
+     */
+    String getPlanSQL();
+
     /**
      * Reset this batch to clear state. This method will be called before each query execution.
      */

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

@@ -95,16 +95,6 @@ public final class JoinBatch {
         this.additionalFilter = additionalFilter;
     }
 
-    /**
-     * Check if the index at the given table filter really supports batching in this query.
-     *
-     * @param joinFilterId joined table filter id
-     * @return {@code true} if index really supports batching in this query
-     */
-    public boolean isBatchedIndex(int joinFilterId) {
-        return filters[joinFilterId].isBatched();
-    }
-
     /**
      * Get the lookup batch for the given table filter.
      *
@@ -413,7 +403,6 @@ public final class JoinBatch {
         private final TableFilter filter;
         private final JoinFilter join;
         private final int id;
-        private final boolean fakeBatch;
 
         private final IndexLookupBatch lookupBatch;
 
@@ -421,16 +410,16 @@ public final class JoinBatch {
             this.filter = filter;
             this.id = filter.getJoinFilterId();
             this.join = join;
-            fakeBatch = lookupBatch == null;
-            this.lookupBatch = fakeBatch ? new FakeLookupBatch(filter) : lookupBatch;
-        }
-
-        private boolean isBatched() {
-            return !fakeBatch;
+            if (lookupBatch == null && id != 0) {
+                lookupBatch = new FakeLookupBatch(filter);
+            }
+            this.lookupBatch = lookupBatch;
         }
 
         private void reset() {
-            lookupBatch.reset();
+            if (lookupBatch != null) {
+                lookupBatch.reset();
+            }
         }
 
         private Row getNullRow() {
@@ -657,6 +646,11 @@ public final class JoinBatch {
             this.filter = filter;
         }
 
+        @Override
+        public String getPlanSQL() {
+            return "fake";
+        }
+
         @Override
         public void reset() {
             full = false;
@@ -722,29 +716,36 @@ public final class JoinBatch {
     private abstract static class ViewIndexLookupBatchBase<R extends QueryRunnerBase> 
             implements IndexLookupBatch {
         protected final ViewIndex viewIndex;
-        protected final ArrayList<Future<Cursor>> result = New.arrayList();
-        protected int resultSize;
-        
+        private final ArrayList<Future<Cursor>> result = New.arrayList();
+        private int resultSize;
+        private boolean findCalled;
+
         protected ViewIndexLookupBatchBase(ViewIndex viewIndex) {
             this.viewIndex = viewIndex;
         }
 
+        @Override
+        public String getPlanSQL() {
+            return "view";
+        }
+
         protected abstract boolean collectSearchRows(R r);
 
         protected abstract R newQueryRunner();
 
-        protected abstract void startQueryRunners();
+        protected abstract void startQueryRunners(int resultSize);
 
         protected final boolean resetAfterFind() {
-            if (resultSize < 0) {
-                // method find was called, we need to reset futures to initial state for reuse
-                for (int i = 0, size = -resultSize; i < size; i++) {
-                    queryRunner(i).reset();
-                }
-                resultSize = 0;
-                return true;
+            if (!findCalled) {
+                return false;
             }
-            return false;
+            findCalled = false;
+            // method find was called, we need to reset futures to initial state for reuse
+            for (int i = 0; i < resultSize; i++) {
+                queryRunner(i).reset();
+            }
+            resultSize = 0;
+            return true;
         }
 
         @SuppressWarnings("unchecked")
@@ -790,12 +791,9 @@ public final class JoinBatch {
             if (resultSize == 0) {
                 return Collections.emptyList();
             }
-            startQueryRunners();
-            List<Future<Cursor>> list  = resultSize == result.size() ?
-                    result : result.subList(0, resultSize);
-            // mark that method find was called
-            resultSize = -resultSize;
-            return list;
+            findCalled = true;
+            startQueryRunners(resultSize);
+            return resultSize == result.size() ? result : result.subList(0, resultSize);
         }
     }
     
@@ -852,17 +850,16 @@ public final class JoinBatch {
 
         @Override
         public boolean isBatchFull() {
-            assert resultSize >= 0;
             return top.isBatchFull();
         }
 
         @Override
-        protected void startQueryRunners() {
+        protected void startQueryRunners(int resultSize) {
             // we do batched find only for top table filter and then lazily run the ViewIndex query
             // for each received top future cursor
             List<Future<Cursor>> topFutureCursors = top.find();
             if (topFutureCursors.size() != resultSize) {
-                throw DbException.throwInternalError("Unexpected result size: " + result.size() +
+                throw DbException.throwInternalError("Unexpected result size: " + topFutureCursors.size() +
                         ", expected :" + resultSize);
             }
             for (int i = 0; i < resultSize; i++) {
@@ -976,15 +973,18 @@ public final class JoinBatch {
         }
 
         @Override
-        protected void startQueryRunners() {
-            for (int i = 0; i < filters.size(); i++) {
-                List<Future<Cursor>> topFutureCursors = filters.get(i).find();
-                for (int j = 0, k = 0; j < resultSize; j++) {
-                    Future<Cursor>[] cs = queryRunner(j).topFutureCursors;
-                    if (cs[j] == null) {
-                        cs[j] = topFutureCursors.get(k++);
+        protected void startQueryRunners(int resultSize) {
+            for (int f = 0; f < filters.size(); f++) {
+                List<Future<Cursor>> topFutureCursors = filters.get(f).find();
+                int r = 0, c = 0;
+                for (; r < resultSize; r++) {
+                    Future<Cursor>[] cs = queryRunner(r).topFutureCursors;
+                    if (cs[f] == null) {
+                        cs[f] = topFutureCursors.get(c++);
                     }
                 }
+                assert r == resultSize;
+                assert c == topFutureCursors.size();
             }
         }
     }

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

@@ -269,8 +269,10 @@ public class TableFilter implements ColumnResolver {
     /**
      * Prepare reading rows. This method will remove all index conditions that
      * can not be used, and optimize the conditions.
+     * 
+     * @param parse if we are parsing sub-query
      */
-    public void prepare() {
+    public void prepare(boolean parse) {
         // forget all unused index conditions
         // the indexConditions list may be modified here
         for (int i = 0; i < indexConditions.size(); i++) {
@@ -289,19 +291,21 @@ public class TableFilter implements ColumnResolver {
             if (SysProperties.CHECK && nestedJoin == this) {
                 DbException.throwInternalError("self join");
             }
-            nestedJoin.prepare();
+            nestedJoin.prepare(parse);
         }
         if (join != null) {
             if (SysProperties.CHECK && join == this) {
                 DbException.throwInternalError("self join");
             }
-            join.prepare();
+            join.prepare(parse);
         }
-        if (filterCondition != null) {
-            filterCondition = filterCondition.optimize(session);
-        }
-        if (joinCondition != null) {
-            joinCondition = joinCondition.optimize(session);
+        if (!parse) {
+            if (filterCondition != null) {
+                filterCondition = filterCondition.optimize(session);
+            }
+            if (joinCondition != null) {
+                joinCondition = joinCondition.optimize(session);
+            }
         }
     }
 
@@ -784,11 +788,16 @@ public class TableFilter implements ColumnResolver {
             buff.append('\n');
             StatementBuilder planBuff = new StatementBuilder();
             if (joinBatch != null) {
-                if (joinBatch.isBatchedIndex(joinFilterId)) {
-                    planBuff.append("batched:true ");
-                } else if (joinFilterId != 0) {
-                    // top table filter does not need to fake batching, it works as usual in this case
-                    planBuff.append("batched:fake ");
+                IndexLookupBatch lookupBatch = joinBatch.getLookupBatch(joinFilterId);
+                if (lookupBatch == null) {
+                    if (joinFilterId != 0) {
+                        throw DbException.throwInternalError();
+                    }
+                } else {
+                    planBuff.append("batched:");
+                    String batchPlan = lookupBatch.getPlanSQL();
+                    planBuff.append(batchPlan);
+                    planBuff.append(" ");
                 }
             }
             planBuff.append(index.getPlanSQL());

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

@@ -24,6 +24,7 @@ import java.util.concurrent.ExecutorService;
 import java.util.concurrent.Executors;
 import java.util.concurrent.Future;
 import java.util.concurrent.ThreadFactory;
+import java.util.concurrent.atomic.AtomicInteger;
 import org.h2.api.TableEngine;
 import org.h2.command.ddl.CreateTableData;
 import org.h2.command.dml.OptimizerHints;
@@ -36,6 +37,7 @@ import org.h2.index.Index;
 import org.h2.index.IndexLookupBatch;
 import org.h2.index.IndexType;
 import org.h2.index.SingleRowCursor;
+import org.h2.jdbc.JdbcConnection;
 import org.h2.message.DbException;
 import org.h2.result.Row;
 import org.h2.result.SearchRow;
@@ -383,10 +385,24 @@ public class TestTableEngines extends TestBase {
         deleteDb("testSubQueryInfo");
     }
 
+    private void setBatchingEnabled(Statement stat, boolean enabled) throws SQLException {
+        stat.execute("SET BATCH_JOINS " + enabled);
+        if (!config.networked) {
+            Session s = (Session) ((JdbcConnection) stat.getConnection()).getSession();
+            assertEquals(enabled, s.isJoinBatchEnabled());
+        }
+    }
+    
     private void testBatchedJoin() throws SQLException {
-        deleteDb("tableEngine");
-        Connection conn = getConnection("tableEngine;OPTIMIZE_REUSE_RESULTS=0");
+        deleteDb("testBatchedJoin");
+        Connection conn = getConnection("testBatchedJoin;OPTIMIZE_REUSE_RESULTS=0;BATCH_JOINS=1");
         Statement stat = conn.createStatement();
+        if (!config.networked) {
+            Session s = (Session) ((JdbcConnection) conn).getSession();
+            assertTrue(s.isJoinBatchEnabled());
+        }
+        setBatchingEnabled(stat, false);
+        setBatchingEnabled(stat, true);
         
         TreeSetIndex.exec = Executors.newFixedThreadPool(8, new ThreadFactory() {
             @Override
@@ -399,6 +415,9 @@ public class TestTableEngines extends TestBase {
         
         enableJoinReordering(false);
         try {
+            doTestBatchedJoinSubQueryUnion(stat);
+            
+            TreeSetIndex.lookupBatches.set(0);
             doTestBatchedJoin(stat, 1, 0, 0);
             doTestBatchedJoin(stat, 0, 1, 0);
             doTestBatchedJoin(stat, 0, 0, 1);
@@ -429,11 +448,13 @@ public class TestTableEngines extends TestBase {
             doTestBatchedJoin(stat, 0, 0, 5);
             doTestBatchedJoin(stat, 0, 8, 1);
             doTestBatchedJoin(stat, 0, 2, 1);
+            
+            assertTrue(TreeSetIndex.lookupBatches.get() > 0);
         } finally {
             enableJoinReordering(true);
             TreeSetIndex.exec.shutdownNow();
         }
-        deleteDb("tableEngine");
+        deleteDb("testBatchedJoin");
     }
     
     /**
@@ -447,7 +468,64 @@ public class TestTableEngines extends TestBase {
         }
         OptimizerHints.set(hints);
     }
-    
+
+    private void checkPlan(Statement stat, String sql) throws SQLException {
+        ResultSet rs = stat.executeQuery("EXPLAIN " + sql);
+        assertTrue(rs.next());
+        String plan = rs.getString(1);
+        assertEquals(normalize(sql), normalize(plan));
+    }
+
+    private static String normalize(String sql) {
+        sql = sql.replace('\n', ' ');
+        return sql.replaceAll("\\s+", " ").trim();
+    }
+
+    private void doTestBatchedJoinSubQueryUnion(Statement stat) throws SQLException {
+        String engine = '"' + TreeSetIndexTableEngine.class.getName() + '"';
+        stat.execute("CREATE TABLE t (a int, b int) ENGINE " + engine);
+        TreeSetTable t = TreeSetIndexTableEngine.created;
+        stat.execute("CREATE INDEX T_IDX_A ON t(a)");
+        stat.execute("CREATE INDEX T_IDX_B ON t(b)");
+        setBatchSize(t, 3);
+        for (int i = 0; i < 20; i++) {
+            stat.execute("insert into t values (" + i + "," + i + ")");
+        }
+        stat.execute("CREATE TABLE u (a int, b int) ENGINE " + engine);
+        TreeSetTable u = TreeSetIndexTableEngine.created;
+        stat.execute("CREATE INDEX U_IDX_A ON u(a)");
+        stat.execute("CREATE INDEX U_IDX_B ON u(b)");
+        setBatchSize(u, 0);
+        for (int i = 0; i < 20; i++) {
+            stat.execute("insert into u values (" + i + "," + i + ")");
+        }
+
+        checkPlan(stat, "SELECT 1 FROM PUBLIC.T T1 /* PUBLIC.\"scan\" */ "
+                + "INNER JOIN PUBLIC.T T2 /* batched:test PUBLIC.T_IDX_B: B = T1.A */ "
+                + "ON 1=1 WHERE T1.A = T2.B");
+        checkPlan(stat, "SELECT 1 FROM PUBLIC.T T1 /* PUBLIC.\"scan\" */ "
+                + "INNER JOIN PUBLIC.T T2 /* batched:test PUBLIC.T_IDX_B: B = T1.A */ "
+                + "ON 1=1 /* WHERE T1.A = T2.B */ "
+                + "INNER JOIN PUBLIC.T T3 /* batched:test PUBLIC.T_IDX_B: B = T2.A */ "
+                + "ON 1=1 WHERE (T2.A = T3.B) AND (T1.A = T2.B)");
+        checkPlan(stat, "SELECT 1 FROM PUBLIC.T T1 /* PUBLIC.\"scan\" */ "
+                + "INNER JOIN PUBLIC.U /* batched:fake PUBLIC.U_IDX_A: A = T1.A */ "
+                + "ON 1=1 /* WHERE T1.A = U.A */ "
+                + "INNER JOIN PUBLIC.T T2 /* batched:test PUBLIC.T_IDX_B: B = U.B */ "
+                + "ON 1=1 WHERE (T1.A = U.A) AND (U.B = T2.B)");
+        checkPlan(stat, "SELECT 1 FROM ( SELECT A FROM PUBLIC.T ) Z "
+                + "/* SELECT A FROM PUBLIC.T /++ PUBLIC.\"scan\" ++/ */ "
+                + "INNER JOIN PUBLIC.T /* batched:test PUBLIC.T_IDX_B: B = Z.A */ "
+                + "ON 1=1 WHERE Z.A = T.B");
+        checkPlan(stat, "SELECT 1 FROM PUBLIC.T /* PUBLIC.\"scan\" */ "
+                + "INNER JOIN ( SELECT A FROM PUBLIC.T ) Z "
+                + "/* batched:view SELECT A FROM PUBLIC.T /++ batched:test PUBLIC.T_IDX_A: A IS ?1 ++/ "
+                + "WHERE A IS ?1: A = T.B */ ON 1=1 WHERE Z.A = T.B");
+
+        stat.execute("DROP TABLE T");
+        stat.execute("DROP TABLE U");
+    }
+
     private void doTestBatchedJoin(Statement stat, int... batchSizes) throws SQLException {
         ArrayList<TreeSetTable> tables = New.arrayList(batchSizes.length);
         
@@ -501,6 +579,9 @@ public class TestTableEngines extends TestBase {
                 fail();
             }
         }
+        for (int i = 0; i < batchSizes.length; i++) {
+            stat.executeUpdate("DROP TABLE IF EXISTS T" + i);
+        }
     }
 
     private static void assert0(boolean condition, String message) {
@@ -512,7 +593,15 @@ public class TestTableEngines extends TestBase {
     private static void setBatchSize(ArrayList<TreeSetTable> tables, int... batchSizes) {
         for (int i = 0; i < batchSizes.length; i++) {
             int batchSize = batchSizes[i];
-            for (Index idx : tables.get(i).getIndexes()) {
+            setBatchSize(tables.get(i), batchSize);
+        }
+    }
+
+    private static void setBatchSize(TreeSetTable t, int batchSize) {
+        if (t.getIndexes() == null) {
+            t.scan.preferedBatchSize = batchSize;
+        } else {
+            for (Index idx : t.getIndexes()) {
                 ((TreeSetIndex) idx).preferedBatchSize = batchSize;
             }
         }
@@ -1115,6 +1204,8 @@ public class TestTableEngines extends TestBase {
      * An index that internally uses a tree set.
      */
     private static class TreeSetIndex extends BaseIndex implements Comparator<SearchRow> {
+        private static AtomicInteger lookupBatches = new AtomicInteger();
+        
         /**
          * Executor service to test batched joins.
          */
@@ -1145,9 +1236,18 @@ public class TestTableEngines extends TestBase {
         public IndexLookupBatch createLookupBatch(final TableFilter filter) {
             assert filter.getMasks() != null || "scan".equals(getName());
             final int preferedSize = preferedBatchSize; 
-            return preferedSize == 0 ? null : new IndexLookupBatch() {
+            if (preferedSize == 0) {
+                return null;
+            }
+            lookupBatches.incrementAndGet();
+            return new IndexLookupBatch() {
                 List<SearchRow> searchRows = New.arrayList();
 
+                @Override
+                public String getPlanSQL() {
+                    return "test";
+                }
+                
                 @Override public boolean isBatchFull() {
                     return searchRows.size() >= preferedSize * 2;
                 }