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Archives of the TeradataForum
Message Posted: Sat, 25 Jun 2005 @ 18:47:59 GMT
| Subj: | | Re: DBC Space management |
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| From: | | Morris, Mark |
If you save off the resusage tables to history note that ResUsage data is highly compressible with multi-value compression. Maybe someone here
has done the analysis and would be willing to share the DDL for resusage history tables with good compression values (my intuition is that the
compressible value set for resusage columns wouldn't be site dependent, but I haven't actually verified that). So I imagine someone is going to
ask why Teradata doesn't compress ResUsage to begin with, and the answer is that the ResUsage rows are inserted in a special way so as to minimize
impact to user workload, and this special path doesn't go through the compression path. I suppose that still begs the question of whether the
ResUsage tables could be created with the DDL for compression values even though the data wouldn't actually be compressed. That way a CREATE AS
statement would inherit the compression values and saved ResUsage history could be compressed without user effort. I'll look into whether that is
feasible.
Mark
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