1 /* 2 3 Derby - Class org.apache.derby.iapi.store.access.DynamicCompiledOpenConglomInfo 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.error.StandardException; 25 26 27 /** 28 29 Information that can be "compiled" and reused per transaction per 30 open operation. This information is read only by the caller and 31 written by user. Likely information kept in this object is a set of 32 scratch buffers which will be used by openScan() and thus must not be 33 shared across multiple threads/openScan()'s/openConglomerate()'s. The 34 goal is to optimize repeated operations like btree inserts, by allowing a 35 set of scratch buffers to be reused across a repeated execution of a statement 36 like an insert/delete/update. 37 38 This information is obtained from the getDynamicCompiledConglomInfo(conglomid) 39 method call. It can then be used in openConglomerate() and openScan() calls 40 for increased performance. The information is only valid until the next 41 ddl operation is performed on the conglomerate. It is up to the caller to 42 provide an invalidation methodology. 43 44 The dynamic info is a set of variables to be used in a given ScanController 45 or ConglomerateController. It can only be used in one controller at a time. 46 It is up to the caller to insure the correct thread access to this info. The 47 type of info in this is a scratch template for btree traversal, other scratch 48 variables for qualifier evaluation, ... 49 50 **/ 51 52 public interface DynamicCompiledOpenConglomInfo 53 { 54 } 55