01: /*
02:
03: Derby - Class org.apache.derby.impl.sql.execute.rts.ResultSetStatistics
04:
05: Licensed to the Apache Software Foundation (ASF) under one or more
06: contributor license agreements. See the NOTICE file distributed with
07: this work for additional information regarding copyright ownership.
08: The ASF licenses this file to you under the Apache License, Version 2.0
09: (the "License"); you may not use this file except in compliance with
10: the License. You may obtain a copy of the License at
11:
12: http://www.apache.org/licenses/LICENSE-2.0
13:
14: Unless required by applicable law or agreed to in writing, software
15: distributed under the License is distributed on an "AS IS" BASIS,
16: WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
17: See the License for the specific language governing permissions and
18: limitations under the License.
19:
20: */
21:
22: package org.apache.derby.impl.sql.execute.rts;
23:
24: /**
25: * The ResultSetStatistics interface is used to provide run time
26: * statistics information on a specific ResultSet.
27: * <p>
28: * This interface extends Formatable so that all objects which implement
29: * this interface can be easily saved to the database.
30: *
31: * @author jerry
32: */
33: public interface ResultSetStatistics {
34: /**
35: * Return the statement execution plan as a String.
36: *
37: * @param depth Indentation level.
38: *
39: * @return String The statement execution plan as a String.
40: */
41: public String getStatementExecutionPlanText(int depth);
42:
43: /**
44: * Return information on the scan nodes from the statement execution
45: * plan as a String.
46: *
47: * @param depth Indentation level.
48: * @param tableName if not NULL then return information for this table only
49: * @return String The information on the scan nodes from the
50: * statement execution plan as a String.
51: */
52: public String getScanStatisticsText(String tableName, int depth);
53:
54: /**
55: * Get the estimated row count for the number of rows returned
56: * by the associated query or statement.
57: *
58: * @return The estimated number of rows returned by the associated
59: * query or statement.
60: */
61: public double getEstimatedRowCount();
62: }
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