Sub-query info added for cost calculation.

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

@@ -84,11 +84,12 @@ class Optimizer {
     }
 
     private void calculateBestPlan() {
-        start = System.currentTimeMillis();
         cost = -1;
         if (filters.length == 1 || !isJoinReorderingEnabled()) {
             testPlan(filters);
-        } else if (filters.length <= MAX_BRUTE_FORCE_FILTERS) {
+        } else {
+            start = System.currentTimeMillis();
+            if (filters.length <= MAX_BRUTE_FORCE_FILTERS) {
                 calculateBruteForceAll();
             } else {
                 calculateBruteForceSome();
@@ -96,6 +97,12 @@ class Optimizer {
                 calculateGenetic();
             }
         }
+    }
+
+    private void calculateFakePlan() {
+        cost = -1;
+        bestPlan = new Plan(filters, filters.length, condition);
+    }
 
     private boolean canStop(int x) {
         if ((x & 127) == 0) {
@@ -234,15 +241,24 @@ class Optimizer {
 
     /**
      * Calculate the best query plan to use.
+     *
+     * @param parse If we do not need to really get the best plan because it is view a parsing stage.
      */
-    void optimize() {
+    void optimize(boolean parse) {
+        if (parse) {
+            calculateFakePlan();
+        } else {
             calculateBestPlan();
             bestPlan.removeUnusableIndexConditions();
+        }
         TableFilter[] f2 = bestPlan.getFilters();
         topFilter = f2[0];
         for (int i = 0; i < f2.length - 1; i++) {
             f2[i].addJoin(f2[i + 1], false, false, null);
         }
+        if (parse) {
+            return;
+        }
         for (TableFilter f : f2) {
             PlanItem item = bestPlan.getItem(f);
             f.setPlanItem(item);

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

@@ -863,7 +863,7 @@ public class Select extends Query {
                 isQuickAggregateQuery = isEverything(optimizable);
             }
         }
-        cost = preparePlan();
+        cost = preparePlan(session.isParsingView());
         if (distinct && session.getDatabase().getSettings().optimizeDistinct &&
                 !isGroupQuery && filters.size() == 1 &&
                 expressions.size() == 1 && condition == null) {
@@ -967,7 +967,7 @@ public class Select extends Query {
         }
     }
 
-    private double preparePlan() {
+    private double preparePlan(boolean parse) {
         TableFilter[] topArray = topFilters.toArray(
                 new TableFilter[topFilters.size()]);
         for (TableFilter t : topArray) {
@@ -975,13 +975,15 @@ public class Select extends Query {
         }
 
         Optimizer optimizer = new Optimizer(topArray, condition, session);
-        optimizer.optimize();
+        optimizer.optimize(parse);
         topTableFilter = optimizer.getTopFilter();
         double planCost = optimizer.getCost();
 
         setEvaluatableRecursive(topTableFilter);
 
+        if (!parse) {
             topTableFilter.prepare();
+        }
         return planCost;
     }
 

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

@@ -5,13 +5,13 @@
  */
 package org.h2.engine;
 
+import java.util.ArrayDeque;
 import java.util.ArrayList;
 import java.util.HashMap;
 import java.util.HashSet;
 import java.util.Iterator;
 import java.util.LinkedList;
 import java.util.Random;
-
 import org.h2.api.ErrorCode;
 import org.h2.command.Command;
 import org.h2.command.CommandInterface;
@@ -33,6 +33,7 @@ import org.h2.schema.Schema;
 import org.h2.store.DataHandler;
 import org.h2.store.InDoubtTransaction;
 import org.h2.store.LobStorageFrontend;
+import org.h2.table.SubQueryInfo;
 import org.h2.table.Table;
 import org.h2.util.New;
 import org.h2.util.SmallLRUCache;
@@ -109,6 +110,8 @@ public class Session extends SessionWithState {
     private final int queryCacheSize;
     private SmallLRUCache<String, Command> queryCache;
     private long modificationMetaID = -1;
+    private ArrayDeque<SubQueryInfo> subQueryInfoStack = new ArrayDeque<SubQueryInfo>();
+    private int parsingView;
 
     /**
      * Temporary LOBs from result sets. Those are kept for some time. The
@@ -142,6 +145,31 @@ public class Session extends SessionWithState {
         this.currentSchemaName = Constants.SCHEMA_MAIN;
     }
 
+    public void pushSubQueryInfo(SubQueryInfo subQueryInfo) {
+        assert subQueryInfo != null;
+        subQueryInfoStack.addLast(subQueryInfo);
+    }
+
+    public void popSubQueryInfo(SubQueryInfo subQueryInfo) {
+        SubQueryInfo popped = subQueryInfoStack.pollLast();
+        assert popped == subQueryInfo;
+    }
+
+    public SubQueryInfo getSubQueryInfo() {
+        return subQueryInfoStack.peekLast();
+    }
+
+    public void setParsingView(boolean parsingView) {
+        // It can be recursive, thus implemented as counter.
+        this.parsingView += parsingView ? 1 : -1;
+        assert this.parsingView >= 0;
+    }
+
+    public boolean isParsingView() {
+        assert parsingView >= 0;
+        return parsingView != 0;
+    }
+
     @Override
     public ArrayList<String> getClusterServers() {
         return new ArrayList<String>();

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

@@ -5,8 +5,6 @@
  */
 package org.h2.index;
 
-import java.util.List;
-import java.util.concurrent.Future;
 import org.h2.engine.Session;
 import org.h2.result.Row;
 import org.h2.result.SearchRow;

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

@@ -17,7 +17,7 @@ import org.h2.result.SearchRow;
  * Note that a single instance of {@link IndexLookupBatch} can be reused for multiple 
  * sequential batched lookups.
  * 
- * @see Index#createLookupBatch(TableFilter)
+ * @see Index#createLookupBatch(org.h2.table.TableFilter)
  * @author Sergi Vladykin
  */
 public interface IndexLookupBatch {

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

@@ -6,8 +6,8 @@
 package org.h2.index;
 
 import java.util.ArrayList;
-
 import org.h2.api.ErrorCode;
+import org.h2.command.Prepared;
 import org.h2.command.dml.Query;
 import org.h2.command.dml.SelectUnion;
 import org.h2.engine.Constants;
@@ -21,6 +21,7 @@ import org.h2.result.SearchRow;
 import org.h2.result.SortOrder;
 import org.h2.table.Column;
 import org.h2.table.IndexColumn;
+import org.h2.table.SubQueryInfo;
 import org.h2.table.TableFilter;
 import org.h2.table.TableView;
 import org.h2.util.IntArray;
@@ -46,6 +47,14 @@ public class ViewIndex extends BaseIndex implements SpatialIndex {
     private Query query;
     private final Session createSession;
 
+    /**
+     * Constructor for the original index in {@link TableView}.
+     *
+     * @param view the table view
+     * @param querySQL the query SQL
+     * @param originalParameters the original parameters
+     * @param recursive if the view is recursive
+     */
     public ViewIndex(TableView view, String querySQL,
             ArrayList<Parameter> originalParameters, boolean recursive) {
         initBaseIndex(view, 0, null, null, IndexType.createNonUnique(false));
@@ -58,8 +67,19 @@ public class ViewIndex extends BaseIndex implements SpatialIndex {
         this.indexMasks = null;
     }
 
+    /**
+     * Constructor for plan item generation. Over this index the query will be executed.
+     *
+     * @param view the table view
+     * @param index the view index
+     * @param session the session
+     * @param masks the masks
+     * @param filters table filters
+     * @param filter current filter
+     * @param sortOrder sort order
+     */
     public ViewIndex(TableView view, ViewIndex index, Session session,
-            int[] masks) {
+            int[] masks, TableFilter[] filters, int filter, SortOrder sortOrder) {
         initBaseIndex(view, 0, null, null, IndexType.createNonUnique(false));
         this.view = view;
         this.querySQL = index.querySQL;
@@ -69,7 +89,7 @@ public class ViewIndex extends BaseIndex implements SpatialIndex {
         this.createSession = session;
         columns = new Column[0];
         if (!recursive) {
-            query = getQuery(session, masks);
+            query = getQuery(session, masks, filters, filter, sortOrder);
         }
     }
 
@@ -129,20 +149,13 @@ public class ViewIndex extends BaseIndex implements SpatialIndex {
                 return cachedCost.cost;
             }
         }
-        Query q = (Query) session.prepare(querySQL, true);
+        Query q = prepareSubQuery(querySQL, session, masks, filters, filter, sortOrder, true);
         if (masks != null) {
-            IntArray paramIndex = new IntArray();
-            for (int i = 0; i < masks.length; i++) {
-                int mask = masks[i];
+            for (int idx = 0; idx < masks.length; idx++) {
+                int mask = masks[idx];
                 if (mask == 0) {
                     continue;
                 }
-                paramIndex.add(i);
-            }
-            int len = paramIndex.size();
-            for (int i = 0; i < len; i++) {
-                int idx = paramIndex.get(i);
-                int mask = masks[idx];
                 int nextParamIndex = q.getParameters().size() + view.getParameterOffset();
                 if ((mask & IndexCondition.EQUALITY) != 0) {
                     Parameter param = new Parameter(nextParamIndex);
@@ -162,7 +175,7 @@ public class ViewIndex extends BaseIndex implements SpatialIndex {
                 }
             }
             String sql = q.getPlanSQL();
-            q = (Query) session.prepare(sql, true);
+            q = prepareSubQuery(sql, session, masks, filters, filter, sortOrder, false);
         }
         double cost = q.getCost();
         cachedCost = new CostElement();
@@ -182,6 +195,19 @@ public class ViewIndex extends BaseIndex implements SpatialIndex {
         return find(filter.getSession(), null, null, intersection);
     }
 
+    private static Query prepareSubQuery(String sql, Session session, int[] masks,
+            TableFilter[] filters, int filter, SortOrder sortOrder, boolean preliminary) {
+        Prepared p;
+        SubQueryInfo info = new SubQueryInfo(masks, filters, filter, sortOrder, preliminary);
+        session.pushSubQueryInfo(info);
+        try {
+            p = session.prepare(sql, true);
+        } finally {
+            session.popSubQueryInfo(info);
+        }
+        return (Query) p;
+    }
+
     private Cursor find(Session session, SearchRow first, SearchRow last,
             SearchRow intersection) {
         if (recursive) {
@@ -284,8 +310,9 @@ public class ViewIndex extends BaseIndex implements SpatialIndex {
         param.setValue(v);
     }
 
-    private Query getQuery(Session session, int[] masks) {
-        Query q = (Query) session.prepare(querySQL, true);
+    private Query getQuery(Session session, int[] masks,
+            TableFilter[] filters, int filter, SortOrder sortOrder) {
+        Query q = prepareSubQuery(querySQL, session, masks, filters, filter, sortOrder, true);
         if (masks == null) {
             return q;
         }
@@ -368,7 +395,7 @@ public class ViewIndex extends BaseIndex implements SpatialIndex {
         }
 
         String sql = q.getPlanSQL();
-        q = (Query) session.prepare(sql, true);
+        q = prepareSubQuery(sql, session, masks, filters, filter, sortOrder, false);
         return q;
     }
 

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

+/*
+ * Copyright 2004-2014 H2 Group. Multiple-Licensed under the MPL 2.0,
+ * and the EPL 1.0 (http://h2database.com/html/license.html).
+ * Initial Developer: H2 Group
+ */
+
+package org.h2.table;
+
+import org.h2.result.SortOrder;
+
+/**
+ * Information about current sub-query being prepared.
+ * 
+ * @author Sergi Vladykin
+ */
+public class SubQueryInfo {
+
+    private int[] masks;
+    private TableFilter[] filters;
+    private int filter;
+    private SortOrder sortOrder;
+    private boolean preliminary;
+
+    /**
+     * @param masks index conditions masks
+     * @param filters table filters
+     * @param filter current filter
+     * @param sortOrder sort order
+     * @param preliminary if this is a preliminary query optimization 
+     *          without global conditions
+     */
+    public SubQueryInfo(int[] masks, TableFilter[] filters, int filter, 
+            SortOrder sortOrder, boolean preliminary) {
+        this.masks = masks;
+        this.filters = filters;
+        this.filter = filter;
+        this.sortOrder = sortOrder;
+        this.preliminary = preliminary;
+    }
+
+    public int[] getMasks() {
+        return masks;
+    }
+
+    public TableFilter[] getFilters() {
+        return filters;
+    }
+
+    public int getFilter() {
+        return filter;
+    }
+
+    public SortOrder getSortOrder() {
+        return sortOrder;
+    }
+
+    public boolean isPreliminary() {
+        return preliminary;
+    }
+}

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

@@ -103,7 +103,13 @@ public class TableView extends Table {
     }
 
     private static Query compileViewQuery(Session session, String sql) {
-        Prepared p = session.prepare(sql);
+        Prepared p;
+        session.setParsingView(true);
+        try {
+            p = session.prepare(sql);
+        } finally {
+            session.setParsingView(false);
+        }
         if (!(p instanceof Query)) {
             throw DbException.getSyntaxError(sql, 0);
         }
@@ -241,7 +247,7 @@ public class TableView extends Table {
         // We cannot hold the lock during the ViewIndex creation or we risk ABBA
         // deadlocks if the view creation calls back into H2 via something like
         // a FunctionTable.
-        ViewIndex i2 = new ViewIndex(this, index, session, masks);
+        ViewIndex i2 = new ViewIndex(this, index, session, masks, filters, filter, sortOrder);
         synchronized (this) {
             // have to check again in case another session has beat us to it
             ViewIndex i3 = indexCache.get(cacheKey);

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

@@ -70,6 +70,7 @@ public class TestTableEngines extends TestBase {
 
     @Override
     public void test() throws Exception {
+        testSubQueryInfo();
         testEarlyFilter();
         testEngineParams();
         testSimpleQuery();
@@ -343,6 +344,20 @@ public class TestTableEngines extends TestBase {
         deleteDb("tableEngine");
     }
 
+    private void testSubQueryInfo() throws SQLException {
+        deleteDb("testSubQueryInfo");
+        Connection conn = getConnection("testSubQueryInfo");
+        Statement stat = conn.createStatement();
+        stat.execute("create table SUB_QUERY_TEST(id int primary key, name varchar) ENGINE \"" +
+                TreeSetIndexTableEngine.class.getName() + "\"");
+        stat.execute("create table t1(id int, birthday date)");
+        stat.executeQuery("select t1.birthday from t1, "
+                + "(select t2.id from sub_query_test t2, "
+                + "(select t3.id from sub_query_test t3 where t3.name = '') t4 "
+                + "where t2.id = t4.id) t5 where t1.id = t5.id");
+        deleteDb("testSubQueryInfo");
+    }
+
     private void testBatchedJoin() throws SQLException {
         deleteDb("tableEngine");
         Connection conn = getConnection("tableEngine;OPTIMIZE_REUSE_RESULTS=0");
@@ -1207,6 +1222,11 @@ public class TestTableEngines extends TestBase {
         @Override
         public double getCost(Session session, int[] masks,
                 TableFilter[] filters, int filter, SortOrder sortOrder) {
+            if (getTable().getName().equals("SUB_QUERY_TEST")) {
+                if (session.getSubQueryInfo() == null) {
+                    throw new IllegalStateException("No qubquery info found.");
+                }
+            }
             return getCostRangeIndex(masks, set.size(), filters, filter, sortOrder);
         }