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Archives of the TeradataForum
Message Posted: Wed, 28 May 2003 @ 14:37:06 GMT
| Subj: | | Re: Alter table vs. create copy for add column |
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| From: | | McBride, Michael |
I prefer the second option if the new column needs to be in any position other than at the end of the table, as the first option (alter
table) will always append the new column to the end of the existing set of columns that define the table...
I also prefer the second option because it retains a copy of the original table for as long as needed / required, albeit at a cost of
disk space, which might be an issue on systems that are already at, or nearly at, capacity!
So one might conclude that the first option is the only way to go when space is at a premium and you don't mind the new column appended
to the end of the existing table, right? Well, here's some food for thought...would it be considered good Data Warehousing practice to run
an alter table command on production tables? What is the back-out plan, or is there one? How long will the end-user be locked out of the
table during an "alter" scenario?
mem
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