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Archives of the TeradataForum
Message Posted: Mon, 30 Jan 2006 @ 23:15:48 GMT
| Subj: | | Primary keys without a Unique Index. |
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| From: | | Joe Celko |
| | Is there any DBMS which supports a PK without implementing it as a
Unique Index? Would be nice to know how it's done (fast and efficient). | |
Look at the compressed bit vectors used by the SAND engine. Another approach that was used in experimental RDBMS projects was via a perfect
hashing algorithm (a perfect hash has no clashes, so when you get one, you know that the key has been used).
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