Remove tricks for distinct operations on non-distinct external results

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

@@ -5,8 +5,6 @@
  */
 package org.h2.mvstore.db;
 
-import java.util.Arrays;
-
 import org.h2.engine.Database;
 import org.h2.expression.Expression;
 import org.h2.message.DbException;
@@ -22,11 +20,6 @@ import org.h2.value.ValueArray;
  */
 class MVPlainTempResult extends MVTempResult {
 
-    /**
-     * The type of the distinct values.
-     */
-    private final ValueDataType distinctType;
-
     /**
      * Map with identities of rows as keys rows as values.
      */
@@ -39,12 +32,6 @@ class MVPlainTempResult extends MVTempResult {
      */
     private long counter;
 
-    /**
-     * Optional index. This index is created only if {@link #contains(Value[])}
-     * method is invoked. Only the root result should have an index if required.
-     */
-    private MVMap<ValueArray, Boolean> index;
-
     /**
      * Cursor for the {@link #next()} method.
      */
@@ -58,7 +45,6 @@ class MVPlainTempResult extends MVTempResult {
      */
     private MVPlainTempResult(MVPlainTempResult parent) {
         super(parent);
-        this.distinctType = null;
         this.map = parent.map;
     }
 
@@ -75,46 +61,20 @@ class MVPlainTempResult extends MVTempResult {
     MVPlainTempResult(Database database, Expression[] expressions, int visibleColumnCount) {
         super(database, expressions.length, visibleColumnCount);
         ValueDataType valueType = new ValueDataType(database.getCompareMode(), database, new int[columnCount]);
-        if (columnCount == visibleColumnCount) {
-            distinctType = valueType;
-        } else {
-            distinctType = new ValueDataType(database.getCompareMode(), database, new int[visibleColumnCount]);
-        }
         Builder<Long, ValueArray> builder = new MVMap.Builder<Long, ValueArray>().valueType(valueType);
         map = store.openMap("tmp", builder);
     }
 
     @Override
     public int addRow(Value[] values) {
-        assert parent == null && index == null;
+        assert parent == null;
         map.put(counter++, ValueArray.get(values));
         return ++rowCount;
     }
 
     @Override
     public boolean contains(Value[] values) {
-        // Only parent result maintains the index
-        if (parent != null) {
-            return parent.contains(values);
-        }
-        if (index == null) {
-            createIndex();
-        }
-        return index.containsKey(ValueArray.get(values));
-    }
-
-    private void createIndex() {
-        Builder<ValueArray, Boolean> builder = new MVMap.Builder<ValueArray, Boolean>().keyType(distinctType);
-        index = store.openMap("idx", builder);
-        Cursor<Long, ValueArray> c = map.cursor(null);
-        while (c.hasNext()) {
-            c.next();
-            ValueArray row = c.getValue();
-            if (columnCount != visibleColumnCount) {
-                row = ValueArray.get(Arrays.copyOf(row.getList(), visibleColumnCount));
-            }
-            index.putIfAbsent(row, true);
-        }
+        throw DbException.getUnsupportedException("contains()");
     }
 
     @Override

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

@@ -171,7 +171,9 @@ class MVSortedTempResult extends MVTempResult {
         } else {
             distinctType = new ValueDataType(database.getCompareMode(), database, new int[visibleColumnCount]);
             if (distinct) {
-                createIndex(false);
+                Builder<ValueArray, Boolean> indexBuilder = new MVMap.Builder<ValueArray, Boolean>()
+                        .keyType(distinctType);
+                index = store.openMap("idx", indexBuilder);
             }
         }
     }
@@ -209,29 +211,13 @@ class MVSortedTempResult extends MVTempResult {
         if (parent != null) {
             return parent.contains(values);
         }
+        assert distinct;
         if (columnCount != visibleColumnCount) {
-            if (index == null) {
-                createIndex(true);
-            }
             return index.containsKey(ValueArray.get(values));
         }
         return map.containsKey(getKey(values));
     }
 
-    private void createIndex(boolean fill) {
-        Builder<ValueArray, Boolean> indexBuilder = new MVMap.Builder<ValueArray, Boolean>()
-                .keyType(distinctType);
-        index = store.openMap("idx", indexBuilder);
-        if (fill) {
-            Cursor<ValueArray, Long> c = map.cursor(null);
-            while (c.hasNext()) {
-                Value[] v = getValue(c.next().getList());
-                ValueArray distinctRow = ValueArray.get(Arrays.copyOf(v, visibleColumnCount));
-                index.putIfAbsent(distinctRow, true);
-            }
-        }
-    }
-
     @Override
     public synchronized ResultExternal createShallowCopy() {
         if (parent != null) {

h2/src/main/org/h2/result/ResultTempTable.java

@@ -144,13 +144,48 @@ public class ResultTempTable implements ResultExternal {
             closeable = new CloseImpl(session, table);
             fileRef = tempFileDeleter.addFile(closeable, this);
         }
-        /*
-         * If ORDER BY or DISTINCT is specified create the index immediately. If
-         * they are not specified index still may be created later if required
-         * for IN (SELECT ...) etc.
-         */
         if (sort != null || distinct) {
-            getIndex();
+            IndexColumn[] indexCols;
+            if (sort != null) {
+                int[] colIndex = sort.getQueryColumnIndexes();
+                int len = colIndex.length;
+                if (distinct) {
+                    BitSet used = new BitSet();
+                    indexCols = new IndexColumn[columnCount];
+                    for (int i = 0; i < len; i++) {
+                        int idx = colIndex[i];
+                        used.set(idx);
+                        IndexColumn indexColumn = createIndexColumn(idx);
+                        indexColumn.sortType = sort.getSortTypes()[i];
+                        indexCols[i] = indexColumn;
+                    }
+                    int idx = 0;
+                    for (int i = len; i < columnCount; i++) {
+                        idx = used.nextClearBit(idx);
+                        indexCols[i] = createIndexColumn(idx);
+                        idx++;
+                    }
+                } else {
+                    indexCols = new IndexColumn[len];
+                    for (int i = 0; i < len; i++) {
+                        IndexColumn indexColumn = createIndexColumn(colIndex[i]);
+                        indexColumn.sortType = sort.getSortTypes()[i];
+                        indexCols[i] = indexColumn;
+                    }
+                }
+            } else {
+                indexCols = new IndexColumn[columnCount];
+                for (int i = 0; i < columnCount; i++) {
+                    indexCols[i] = createIndexColumn(i);
+                }
+            }
+            String indexName = table.getSchema().getUniqueIndexName(session, table, Constants.PREFIX_INDEX);
+            int indexId = session.getDatabase().allocateObjectId();
+            IndexType indexType = IndexType.createNonUnique(true);
+            index = table.addIndex(session, indexName, indexId, indexCols, indexType, true, null);
+            if (closeable != null) {
+                closeable.index = index;
+            }
         }
     }
 
@@ -171,50 +206,6 @@ public class ResultTempTable implements ResultExternal {
         if (parent != null) {
             return parent.getIndex();
         }
-        if (index != null) {
-            return index;
-        }
-        IndexColumn[] indexCols;
-        if (sort != null) {
-            int[] colIndex = sort.getQueryColumnIndexes();
-            int len = colIndex.length;
-            if (distinct) {
-                BitSet used = new BitSet();
-                indexCols = new IndexColumn[columnCount];
-                for (int i = 0; i < len; i++) {
-                    int idx = colIndex[i];
-                    used.set(idx);
-                    IndexColumn indexColumn = createIndexColumn(idx);
-                    indexColumn.sortType = sort.getSortTypes()[i];
-                    indexCols[i] = indexColumn;
-                }
-                int idx = 0;
-                for (int i = len; i < columnCount; i++) {
-                    idx = used.nextClearBit(idx);
-                    indexCols[i] = createIndexColumn(idx);
-                    idx++;
-                }
-            } else {
-                indexCols = new IndexColumn[len];
-                for (int i = 0; i < len; i++) {
-                    IndexColumn indexColumn = createIndexColumn(colIndex[i]);
-                    indexColumn.sortType = sort.getSortTypes()[i];
-                    indexCols[i] = indexColumn;
-                }
-            }
-        } else {
-            indexCols = new IndexColumn[columnCount];
-            for (int i = 0; i < columnCount; i++) {
-                indexCols[i] = createIndexColumn(i);
-            }
-        }
-        String indexName = table.getSchema().getUniqueIndexName(session, table, Constants.PREFIX_INDEX);
-        int indexId = session.getDatabase().allocateObjectId();
-        IndexType indexType = IndexType.createNonUnique(true);
-        index = table.addIndex(session, indexName, indexId, indexCols, indexType, true, null);
-        if (closeable != null) {
-            closeable.index = index;
-        }
         return index;
     }