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Re: Uniquely identifying a record in SQL without a unique key?



fixed

<quote>So we want to be able to display records without acquiring update locks on them, but to be able to go back into any one those records with absolute certainty that it's the right record, acquire an update lock, and update it. </quote>

If the table has duplicate records, you can't ensure to update a specific record of duplicate rows. The only way to give a resultset a specific order is an order by clause, but duplicates could not be ordered and pulling the same Resultset twice, you could get the duplicates in another sequence (e.g.: a tablescan might be implemented in parallel on a machine with multiple CPUs)

D*B






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