Re: Primary Key on Column ?

Gary Myers (101355.3556_at_CompuServe.COM) wrote:
: At table level, the key can comprise more than one column. For example an
: item may have a key of contract number, item number, and so should be defined
: at table level. The contract would have the key contract no which could be
: set at either column or table level. A single column primary key is normally
: faster, but I don't think it makes any difference if its done at table or column
: level. I'd define all keys at the table level for consistency purposes.
: Gary
: --
: Gary Myers, Analyst/Programmer, Kaisha Technology, West of England

Good point about multiple columns - otherwise the only difference is the syntax. The only result is the creation of a unique index on the column(s) specified.

Remember that you should also specify the storage clause for the index tablespace that you want to use as well as some sizing info - this pretty much makes you declare the whole darn thing at table level as opposed to column level. Also give the constraint a readable name instead of the lousy system generated index name - it'll help later.

Good Luck -
Randy :)

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