6.1  Considerations concerning data porting

Data porting describes the steps that are necessary to get data from one 

database to another one. In general, you have to unload (also referred to as 

dump

 or 

export

) the data from the source database into one or more files, and 

load (also referred to as 

import

) the files into the target database.

Database systems provide commands and tools for unloading and loading data. 

In MySQL the 

mysqldump

 tool is for unloading a database. DB2 UDB provides 

the

LOAD 

and

 IMPORT

 commands for loading data from files into the database.

You have to be aware of differences in how specific data types are represented 

by different database systems. For example, the representation of date and time 

values may be different in different databases, and it is often depends on the 

local settings of the system.

If the source and the target database use different formats, you need to convert 

the data either automatically by tools or manually. Otherwise, the loading tool 

cannot understand the data to load due to the wrong format.

The migration of binary data stored in BLOBs should be done manually because 

binary data cannot be exported to files in a text format.

Porting the user account management is a very specific step in a migration 

project. You need to get the information about users, access rights, and 

privileges out of MySQL, convert it to DB2 specific security information, and 

create the users in DB2 UDB according to the source data. Migrating encrypted 

passwords is impossible in most cases.

6.1.1  Commands and tools supporting data porting

MySQL and DB2 UDB provide tools that support data porting between these two 

systems. In MySQL the 

mysqldump

 utility is used to retrieved data from the 

database; the 

LOAD

 and 

IMPORT

 commands can be used to get this data into DB2 

UDB.

MTK automates the use of the 

mysqldump

 utility and the DB2

LOAD

command.

The mysqldump tool

When porting application data, this tool can be used for retrieving the data from 

MySQL tables. It is shipped with MySQL and is usually located in the

bin 

directory of the MySQL installation.

The basic usage of the 

mysqldump

 tool is as follows:

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MySQL to DB2 UDB Conversion Guide