Merge branch 'master' of https://github.com/h2database/h2database into lazyQuery

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

@@ -872,7 +872,7 @@ public class Select extends Query {
                 Column column = ((ExpressionColumn) expr).getColumn();
                 int selectivity = column.getSelectivity();
                 Index columnIndex = topTableFilter.getTable().
-                        getIndexForColumn(column);
+                        getIndexForColumn(column, false, true);
                 if (columnIndex != null &&
                         selectivity != Constants.SELECTIVITY_DEFAULT &&
                         selectivity < 20) {

h2/src/main/org/h2/expression/Aggregate.java

@@ -287,7 +287,7 @@ public class Aggregate extends Expression {
             case MIN:
             case MAX:
                 boolean first = type == MIN;
-                Index index = getColumnIndex();
+                Index index = getMinMaxColumnIndex();
                 int sortType = index.getIndexColumns()[0].sortType;
                 if ((sortType & SortOrder.DESCENDING) != 0) {
                     first = !first;
@@ -575,14 +575,14 @@ public class Aggregate extends Expression {
         return text + StringUtils.enclose(on.getSQL());
     }
 
-    private Index getColumnIndex() {
+    private Index getMinMaxColumnIndex() {
         if (on instanceof ExpressionColumn) {
             ExpressionColumn col = (ExpressionColumn) on;
             Column column = col.getColumn();
             TableFilter filter = col.getTableFilter();
             if (filter != null) {
                 Table table = filter.getTable();
-                Index index = table.getIndexForColumn(column);
+                Index index = table.getIndexForColumn(column, true, false);
                 return index;
             }
         }
@@ -602,7 +602,7 @@ public class Aggregate extends Expression {
                 return visitor.getTable().canGetRowCount();
             case MIN:
             case MAX:
-                Index index = getColumnIndex();
+                Index index = getMinMaxColumnIndex();
                 return index != null;
             default:
                 return false;

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

@@ -377,6 +377,11 @@ public abstract class BaseIndex extends SchemaObjectBase implements Index {
         return -1;
     }
 
+    @Override
+    public boolean isFirstColumn(Column column) {
+        return column.equals(columns[0]);
+    }
+
     /**
      * Get the list of columns as a string.
      *

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

@@ -190,6 +190,14 @@ public interface Index extends SchemaObject {
      */
     int getColumnIndex(Column col);
 
+    /**
+     * Check if the given column is the first for this index
+     *
+     * @param column the column
+     * @return true if the given columns is the first
+     */
+    boolean isFirstColumn(Column column);
+
     /**
      * Get the indexed columns as index columns (with ordering information).
      *

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

@@ -82,6 +82,14 @@ public class MetaIndex extends BaseIndex {
         return super.getColumnIndex(col);
     }
 
+    @Override
+    public boolean isFirstColumn(Column column) {
+        if (scan) {
+            return false;
+        }
+        return super.isFirstColumn(column);
+    }
+
     @Override
     public void checkRename() {
         throw DbException.getUnsupportedException("META");

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

@@ -230,6 +230,11 @@ public class MultiVersionIndex implements Index {
         return base.getColumnIndex(col);
     }
 
+    @Override
+    public boolean isFirstColumn(Column column) {
+        return base.isFirstColumn(column);
+    }
+
     @Override
     public Column[] getColumns() {
         return base.getColumns();

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

@@ -464,6 +464,11 @@ public class PageDataIndex extends PageIndex {
         return -1;
     }
 
+    @Override
+    public boolean isFirstColumn(Column column) {
+        return false;
+    }
+
     @Override
     public void close(Session session) {
         if (trace.isDebugEnabled()) {

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

@@ -96,6 +96,11 @@ public class PageDelegateIndex extends PageIndex {
         return -1;
     }
 
+    @Override
+    public boolean isFirstColumn(Column column) {
+        return getColumnIndex(column) == 0;
+    }
+
     @Override
     public double getCost(Session session, int[] masks,
             TableFilter[] filters, int filter, SortOrder sortOrder,

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

@@ -222,6 +222,11 @@ public class ScanIndex extends BaseIndex {
         return -1;
     }
 
+    @Override
+    public boolean isFirstColumn(Column column) {
+        return false;
+    }
+
     @Override
     public void checkRename() {
         throw DbException.getUnsupportedException("SCAN");

h2/src/main/org/h2/mvstore/db/MVDelegateIndex.java

@@ -88,6 +88,11 @@ public class MVDelegateIndex extends BaseIndex implements MVIndex {
         return -1;
     }
 
+    @Override
+    public boolean isFirstColumn(Column column) {
+        return getColumnIndex(column) == 0;
+    }
+
     @Override
     public double getCost(Session session, int[] masks,
             TableFilter[] filters, int filter, SortOrder sortOrder,

h2/src/main/org/h2/mvstore/db/MVPrimaryIndex.java

@@ -242,6 +242,11 @@ public class MVPrimaryIndex extends BaseIndex {
         return -1;
     }
 
+    @Override
+    public boolean isFirstColumn(Column column) {
+        return false;
+    }
+
     @Override
     public void remove(Session session) {
         TransactionMap<Value, Value> map = getMap(session);

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

@@ -1050,22 +1050,34 @@ public abstract class Table extends SchemaObjectBase {
      * This method returns null if no matching index is found.
      *
      * @param column the column
+     * @param needGetFirstOrLast if the returned index must be able
+     *          to do {@link Index#canGetFirstOrLast()}
+     * @param needFindNext if the returned index must be able to do
+     *          {@link Index#findNext(Session, SearchRow, SearchRow)}
      * @return the index or null
      */
-    public Index getIndexForColumn(Column column) {
+    public Index getIndexForColumn(Column column,
+            boolean needGetFirstOrLast, boolean needFindNext) {
         ArrayList<Index> indexes = getIndexes();
+        Index result = null;
         if (indexes != null) {
             for (int i = 1, size = indexes.size(); i < size; i++) {
                 Index index = indexes.get(i);
-                if (index.canGetFirstOrLast()) {
-                    int idx = index.getColumnIndex(column);
-                    if (idx == 0) {
-                        return index;
+                if (needGetFirstOrLast && !index.canGetFirstOrLast()) {
+                    continue;
                 }
+                if (needFindNext && !index.canFindNext()) {
+                    continue;
                 }
+                // choose the minimal covering index with the needed first column
+                // to work consistently with execution plan from Optimizer
+                if (index.isFirstColumn(column) && (result == null ||
+                        result.getColumns().length > index.getColumns().length)) {
+                    result = index;
                 }
             }
-        return null;
+        }
+        return result;
     }
 
     public boolean getOnCommitDrop() {

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

@@ -18,6 +18,8 @@ import java.sql.Statement;
  */
 public class TestIndexHints extends TestBase {
 
+    private Connection conn;
+
     /**
      * Run just this test.
      *
@@ -39,11 +41,12 @@ public class TestIndexHints extends TestBase {
         testPlanSqlHasIndexesInCorrectOrder();
         testWithTableAlias();
         testWithTableAliasCalledUse();
+        conn.close();
         deleteDb("indexhints");
     }
 
     private void createDb() throws SQLException {
-        Connection conn = getConnection("indexhints");
+        conn = getConnection("indexhints");
         Statement stat = conn.createStatement();
         stat.execute("create table test (x int, y int)");
         stat.execute("create index idx1 on test (x)");
@@ -52,7 +55,6 @@ public class TestIndexHints extends TestBase {
     }
 
     private void testQuotedIdentifier() throws SQLException {
-        Connection conn = getConnection("indexhints");
         Statement stat = conn.createStatement();
         ResultSet rs = stat.executeQuery("explain analyze select * " +
                 "from test use index(\"Idx3\") where x=1 and y=1");
@@ -66,54 +68,44 @@ public class TestIndexHints extends TestBase {
         plan = rs.getString(1);
         assertTrue(plan.contains("/* PUBLIC.\"Idx3\":"));
         assertTrue(plan.contains("USE INDEX (\"Idx3\")"));
-        conn.close();
     }
 
     private void testWithSingleIndexName() throws SQLException {
-        Connection conn = getConnection("indexhints");
         Statement stat = conn.createStatement();
         ResultSet rs = stat.executeQuery("explain analyze select * " +
                 "from test use index(idx1) where x=1 and y=1");
         rs.next();
         String result = rs.getString(1);
         assertTrue(result.contains("/* PUBLIC.IDX1:"));
-        conn.close();
     }
 
     private void testWithTableAlias() throws SQLException {
-        Connection conn = getConnection("indexhints");
         Statement stat = conn.createStatement();
         ResultSet rs = stat.executeQuery("explain analyze select * " +
                 "from test t use index(idx2) where x=1 and y=1");
         rs.next();
         String result = rs.getString(1);
         assertTrue(result.contains("/* PUBLIC.IDX2:"));
-        conn.close();
     }
 
     private void testWithTableAliasCalledUse() throws SQLException {
         // make sure that while adding new syntax for table hints, code
         // that uses "USE" as a table alias still works
-        Connection conn = getConnection("indexhints");
         Statement stat = conn.createStatement();
         stat.executeQuery("explain analyze select * " +
                 "from test use where use.x=1 and use.y=1");
-        conn.close();
     }
 
     private void testWithMultipleIndexNames() throws SQLException {
-        Connection conn = getConnection("indexhints");
         Statement stat = conn.createStatement();
         ResultSet rs = stat.executeQuery("explain analyze select * " +
                 "from test use index(idx1, idx2) where x=1 and y=1");
         rs.next();
         String result = rs.getString(1);
         assertTrue(result.contains("/* PUBLIC.IDX2:"));
-        conn.close();
     }
 
     private void testPlanSqlHasIndexesInCorrectOrder() throws SQLException {
-        Connection conn = getConnection("indexhints");
         ResultSet rs = conn.createStatement().executeQuery("explain analyze select * " +
                 "from test use index(idx1, idx2) where x=1 and y=1");
         rs.next();
@@ -123,23 +115,18 @@ public class TestIndexHints extends TestBase {
                 "from test use index(idx2, idx1) where x=1 and y=1");
         rs2.next();
         assertTrue(rs2.getString(1).contains("USE INDEX (IDX2, IDX1)"));
-
-        conn.close();
     }
 
     private void testWithEmptyIndexHintsList() throws SQLException {
-        Connection conn = getConnection("indexhints");
         Statement stat = conn.createStatement();
         ResultSet rs = stat.executeQuery("explain analyze select * " +
                 "from test use index () where x=1 and y=1");
         rs.next();
         String result = rs.getString(1);
         assertTrue(result.contains("/* PUBLIC.TEST.tableScan"));
-        conn.close();
     }
 
     private void testWithInvalidIndexName() throws SQLException {
-        Connection conn = getConnection("indexhints");
         Statement stat = conn.createStatement();
         try {
             stat.executeQuery("explain analyze select * " +
@@ -148,8 +135,6 @@ public class TestIndexHints extends TestBase {
                     + "Index \"IDX_DOESNT_EXIST\" not found");
         } catch (SQLException e) {
             assertEquals(ErrorCode.INDEX_NOT_FOUND_1, e.getErrorCode());
-        } finally {
-            conn.close();
         }
     }