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Java > Open Source Codes > org > apache > derby > iapi > store > access > StaticCompiledOpenConglomInfo


1 /*
2
3    Derby - Class org.apache.derby.iapi.store.access.StaticCompiledOpenConglomInfo
4
5    Licensed to the Apache Software Foundation (ASF) under one or more
6    contributor license agreements. See the NOTICE file distributed with
7    this work for additional information regarding copyright ownership.
8    The ASF licenses this file to you under the Apache License, Version 2.0
9    (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.iapi.store.access;
23
24 import org.apache.derby.iapi.types.DataValueDescriptor;
25
26 import org.apache.derby.iapi.services.io.Storable;
27
28 import org.apache.derby.iapi.error.StandardException;
29
30
31 /**
32
33   Information that can be "compiled" once and then used over and over again
34   at execution time. This information is read only by both the caller and
35   the user, thus can be shared by multiple threads/transactions once created.
36
37   This information is obtained from the getStaticCompiledConglomInfo(conglomid)
38   method call. It can then be used in openConglomerate() and openScan() calls
39   for increased performance. The information is only valid until the next
40   ddl operation is performed on the conglomerate. It is up to the caller to
41   provide an invalidation methodology.
42
43   The static info would be valid until any ddl was executed on the conglomid,
44   and would be up to the caller to throw away when that happened. This ties in
45   with what language already does for other invalidation of static info. The
46   type of info in this would be containerid and array of format id's from which
47   templates can be created. The info in this object is read only and can
48   be shared among as many threads as necessary.
49
50 **/
51
52 public interface StaticCompiledOpenConglomInfo extends Storable
53 {
54     /**
55      * routine for internal use of store only.
56      **/
57     DataValueDescriptor getConglom();
58 }
59
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