Adding JMCR-Stable version

[Benchmarks_CSolver.git] / JMCR-Stable / real-world application / derby-10.3.2.1 / java / engine / org / apache / derby / iapi / sql / compile / RequiredRowOrdering.java

diff --git a/JMCR-Stable/real-world application/derby-10.3.2.1/java/engine/org/apache/derby/iapi/sql/compile/RequiredRowOrdering.java b/JMCR-Stable/real-world application/derby-10.3.2.1/java/engine/org/apache/derby/iapi/sql/compile/RequiredRowOrdering.java
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+++ b/JMCR-Stable/real-world application/derby-10.3.2.1/java/engine/org/apache/derby/iapi/sql/compile/RequiredRowOrdering.java
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+/*\r
+\r
+   Derby - Class org.apache.derby.iapi.sql.compile.RequiredRowOrdering\r
+\r
+   Licensed to the Apache Software Foundation (ASF) under one or more\r
+   contributor license agreements.  See the NOTICE file distributed with\r
+   this work for additional information regarding copyright ownership.\r
+   The ASF licenses this file to you under the Apache License, Version 2.0\r
+   (the "License"); you may not use this file except in compliance with\r
+   the License.  You may obtain a copy of the License at\r
+\r
+      http://www.apache.org/licenses/LICENSE-2.0\r
+\r
+   Unless required by applicable law or agreed to in writing, software\r
+   distributed under the License is distributed on an "AS IS" BASIS,\r
+   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.\r
+   See the License for the specific language governing permissions and\r
+   limitations under the License.\r
+\r
+ */\r
+\r
+package org.apache.derby.iapi.sql.compile;\r
+\r
+import org.apache.derby.iapi.error.StandardException;\r
+\r
+import org.apache.derby.iapi.util.JBitSet;\r
+\r
+/**\r
+ * This interface provides a representation of the required ordering of rows\r
+ * from a ResultSet.  Different operations can require ordering: ORDER BY,\r
+ * DISTINCT, GROUP BY.  Some operations, like ORDER BY, require that the\r
+ * columns be ordered a particular way, while others, like DISTINCT and\r
+ * GROUP BY, reuire only that there be no duplicates in the result.\r
+ */\r
+public interface RequiredRowOrdering\r
+{\r
+       static final int SORT_REQUIRED = 1;\r
+       static final int ELIMINATE_DUPS = 2;\r
+       static final int NOTHING_REQUIRED = 3;\r
+\r
+       /**\r
+        * Tell whether sorting is required for this RequiredRowOrdering,\r
+        * given a RowOrdering.\r
+        *\r
+        * @param rowOrdering   The order of rows in question\r
+        *\r
+        * @return      SORT_REQUIRED if sorting is required,\r
+        *                      ELIMINATE_DUPS if no sorting is required but duplicates\r
+        *                                                      must be eliminated (i.e. the rows are in\r
+        *                                                      the right order but there may be duplicates),\r
+        *                      NOTHING_REQUIRED is no operation is required\r
+        *\r
+        * @exception StandardException         Thrown on error\r
+        */\r
+       int sortRequired(RowOrdering rowOrdering) throws StandardException;\r
+\r
+       /**\r
+        * Tell whether sorting is required for this RequiredRowOrdering,\r
+        * given a RowOrdering representing a partial join order, and\r
+        * a bit map telling what tables are represented in the join order.\r
+        * This is useful for reducing the number of cases the optimizer\r
+        * has to consider.\r
+        *\r
+        * @param rowOrdering   The order of rows in the partial join order\r
+        * @param tableMap              A bit map of the tables in the partial join order\r
+        *\r
+        * @return      SORT_REQUIRED if sorting is required,\r
+        *                      ELIMINATE_DUPS if no sorting is required by duplicates\r
+        *                                                      must be eliminated (i.e. the rows are in\r
+        *                                                      the right order but there may be duplicates),\r
+        *                      NOTHING_REQUIRED is no operation is required\r
+        *\r
+        * @exception StandardException         Thrown on error\r
+        */\r
+       int sortRequired(RowOrdering rowOrdering, JBitSet tableMap)\r
+                       throws StandardException;\r
+\r
+       /**\r
+        * Estimate the cost of doing a sort for this row ordering, given\r
+        * the number of rows to be sorted.  This does not take into account\r
+        * whether the sort is really needed.  It also estimates the number of\r
+        * result rows.\r
+        *\r
+        * @param estimatedInputRows    The estimated number of rows to sort\r
+        * @param rowOrdering                   The ordering of the input rows\r
+        * @param resultCost                    A place to store the resulting cost\r
+        *\r
+        * @exception StandardException         Thrown on error\r
+        */\r
+       void estimateCost(double estimatedInputRows,\r
+                                               RowOrdering rowOrdering,\r
+                                               CostEstimate resultCost)\r
+                                       throws StandardException;\r
+\r
+       /**\r
+        * Indicate that a sort is necessary to fulfill this required ordering.\r
+        * This method may be called many times during a single optimization.\r
+        */\r
+       void sortNeeded();\r
+\r
+       /**\r
+        * Indicate that a sort is *NOT* necessary to fulfill this required\r
+        * ordering.  This method may be called many times during a single\r
+        * optimization.\r
+        */\r
+       void sortNotNeeded();\r
+\r
+       boolean getSortNeeded();\r
+}\r