[Db-derby Wiki] Update of "MysqlDerbyMigration/DesignDocument" by RaminMoazeni

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The following page has been changed by RaminMoazeni:
http://wiki.apache.org/db-derby/MysqlDerbyMigration/DesignDocument

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  == Ramin Moazeni ==
  
- == Version 1.1 ==
+ == Version 1.2 ==
  
    
  = Introduction =
@@ -209, +209 @@

    </table>
  </database> }}}
  
+ The DdlUtils tool handles datatype mappings using JDBC datatypes rather than SQL datatypes which are
+ database dependent. Looking at http://db.apache.org/ddlutils/database-support.html, we can see the datatype mapping between JDBC types and SQL types. For example, a TIINYINT datatype from MySQL, will be mapped to SMALLINT in Derby.
  
- In order to use DdlUtils component to migrate the source database to the target database, following steps are suggested: 
+ Please note that the DdlUtils doesn’t support views, constraints (CHECK constraint), triggers, stored procedures, etc. A possible solution would be to execute database-specific commands or to read source database system tables to capture required information. As an example, MySQL provide the following SHOW commands to capture the exact string that was used to create the original object:
  
-  * Capture DDL file from DdlUtils. 
-  * Modify the source DDL to the target DDL using Serialization and Deserialization of XML. 
-  * Fed in the new DDL file to the DdlUtils. 
+ || SHOW CREATE TABLE ||
+ || SHOW CREATE VIEW ||
+ || SHOW DATABASES ||
+ || SHOW TRIGGERS ||
+ || SHOW CREATE PROCEDURE ||
+ || SHOW CREATE FUNCTION ||
  
- In order to easily work with XML files, the use of Serialization and Deserialization of XML is suggested. XML files can be deserialized to Java objects. Therefore, we are dealing with objects afterwards. After modifying the value of object attributes based on datatype mappings of table 1, objects can be serialized to XML files and be used by the DdlUtils to create the corresponding database.
+ = Recommended Approach =
  
- Please note that the DdlUtils doesn’t support non-table entities, constraints, triggers, stored procedures, etc. A possible solution would be to execute database-specific commands to capture required information.
+ I suggest that the DatabaseMetaData approach is used for implemntation of the MySQL to Derby Migration tool for migration of view, constraints, and stored procedures and use the DdlUtils component for migration of database tables.
+ 
+ = Performance =
+ 
+ In order to improve performance, the batch update facility can be used to allow multiple update operations to be submitted to a data source for processing at once. The Statement object can keep track of a list of commands that can be submitted together for execution. The Statement.addBatch method can be used to add commands to a statement’s batch by providing it with the SQL command that needs to be added.
+ 
+ 
+ Submitting multiple updates together, instead of single updates, can greatly improve performance. 
+ 
+ 
+ = Internationalization =
+ 
+ 
  
  = Initial Prototypes =