dynamiccompiledopenconglominfo.java

derby database source code.good for you.

/*

   Derby - Class org.apache.derby.iapi.store.access.DynamicCompiledOpenConglomInfo

   Copyright 2000, 2004 The Apache Software Foundation or its licensors, as applicable.

   Licensed under the Apache License, Version 2.0 (the "License");
   you may not use this file except in compliance with the License.
   You may obtain a copy of the License at

      http://www.apache.org/licenses/LICENSE-2.0

   Unless required by applicable law or agreed to in writing, software
   distributed under the License is distributed on an "AS IS" BASIS,
   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
   See the License for the specific language governing permissions and
   limitations under the License.

 */

package org.apache.derby.iapi.store.access;

import org.apache.derby.iapi.error.StandardException;


/**

  Information that can be "compiled" and reused per transaction per 
  open operation.  This information is read only by the caller and
  written by user.  Likely information kept in this object is a set of
  scratch buffers which will be used by openScan() and thus must not be
  shared across multiple threads/openScan()'s/openConglomerate()'s.  The
  goal is to optimize repeated operations like btree inserts, by allowing a
  set of scratch buffers to be reused across a repeated execution of a statement
  like an insert/delete/update.

  This information is obtained from the getDynamicCompiledConglomInfo(conglomid)
  method call.  It can then be used in openConglomerate() and openScan() calls
  for increased performance.  The information is only valid until the next
  ddl operation is performed on the conglomerate.  It is up to the caller to
  provide an invalidation methodology.
  
  The dynamic info is a set of variables to be used in a given ScanController
  or ConglomerateController.  It can only be used in one controller at a time.
  It is up to the caller to insure the correct thread access to this info.  The
  type of info in this is a scratch template for btree traversal, other scratch
  variables for qualifier evaluation, ...

**/

public interface DynamicCompiledOpenConglomInfo
{
}