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Message Posted: Thu, 18 Aug 2005 @ 08:17:12 GMT

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On Wed, 17 Aug 2005 14:31:26 -0400, TeradataForum wrote:

          >3) delete from test1 where substr(rowid,9,1) > '01'xb;

This Type of usage is one of the reasons we now disallow this.

Your assumption here is a HASH Duplicate means you have a Duplicate Row.

What about 2 different values which generate the same HASH value. Called a HASH SYNONYM. You just deleted rows which weren't duplicates. OOPS.

Also you are are assuming you have < 256 duplicates since the UNIQ[0] will equal 0x00 when we reach 256 hash duplicates and every 256th value after that.

Bad things happen when you make assumptions about the way something is implemented.

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