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Archives of the TeradataForum
Message Posted: Wed, 15 Mar 2006 @ 23:42:43 GMT
| Subj: | | Re: AUTO_NUMBER in Teradata |
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| From: | | Victor Sokovin |
| | Where did you get an idea like this? First of all, a column is not a field. Next, a key is **by definition** a subset of the columns of a
table, NOT a generated value based on the enternal state of the hardware at the time of insertion. Why do you disregard 30+ years of RDBMS to
mimic a sequential magnetic tape file? What do you use to validate and verify this customer number? (answer: you cannot ever validate or verify
such a non-relational thing!). | |
I am not going to comment on differences between columns and fields and I have just posted my opinion on the use of identity columns: I would
not recommend them for something important.
However, identity columns can be useful in some cases. Suppose we have stock quotes / news live feed which we want to load into the database in
real time. The items come in in random order, some of them might be duplicated, some can have invalid structure, etc. No validation can be done,
the data just needs to be made available for downstream systems which will perform further analysis. In this case, identity columns can provide a
good and easy surrogate PI.
Regards,
Victor
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