Moving target

Strolling around the internet, I came across an article of Roman Melnyk about moving data between DB2 databases. Usually you'd try to do a backup and restore, but sometimes you have to use the tools Roman described, db2move and maybe db2look, too.

We're using those two command line programs since choosing DB2 (v7) as part of the platform for our web applications. They are very useful if you need to copy a whole database but don't have the time to take the source database offline for backup. Or if you just want to copy a part of a database.

When changing the hardware platform for our DB2 servers from Intel to Power hardware we discovered another reason for using db2move and db2look: The x86 architecture is a little-endian one, placing the least significant byte of a multiple byte integer first, while the Power CPU is working big-endian. (See http://en.wikipedia.org/wiki/Endianness for details. I guess you could start a holy war about these two philosophies.) This inhibits the backup/restore strategy totally if you need to copy data between these two platforms.

Although the article was published 2004 the topic won't get out of date and if you need to know how to transfer data between DB2 systems it's worth reading.

P.S.: Of course big-endian is the right way to look at data. ;-)

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