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Message Posted: Thu, 04 Oct 2012 @ 09:08:20 GMT

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Hi all,

In my shop, in Q2 this year, we bought 2 2690 machines and migrated the data from the old boxes towards the new ones.

We did this by using a following the procedure as explained in TD book - "Migrating data to Teradata Database Release 13.10" (B035-5927- 080K).

We used ARCMAIN to migrate the data. When the operation had completed, we noticed to our great surprise, nothing got compressed although the automatic hardware compression was set to "on".

The reason was, on the old machines, there was no HW compression so ARCMAIN just restored the tables as they were. Afterwards when you loaded a tab1 for instance fastload into tab1_new.( copy of tab1) than tab1_new got compressed.

To compress the other tables, we had to use the ferret utility with the compress command.

Now, all our tables are compressed, with very spectacular results. (avg 50% compression or even more). The overhead of CPU seems to be low.

But if needed, one can always use the ferret tool to uncompress a table.

Regards,

R.

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