Archives of the TeradataForum
Message Posted: Mon, 30 Jan 2006 @ 23:15:48 GMT
| Subj: || || Primary keys without a Unique Index. |
| 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).