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EJB programming & troubleshooting: CMP bean without a primary key & all columns nullable

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  1. CMP bean without a primary key & all columns nullable (3 messages)

    Is it possible to make a CMP without a primary key and have all other columns nullable, is this supported by WAS 4.0
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  2. CMP bean without a primary key & all columns nullable[ Go to top ]

    No, a CMP EntityBean must have a primary key. What is the point of having a database table without primary key - since you can't uniquely identify rows?

    Daniel.
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  3. CMP bean without a primary key & all columns nullable[ Go to top ]

    There are many reasons for this kind of table.

    What about a table which is auditing changes to things. It just tends to be a table with increasing date time, and then other data. Typically under high load, a key (and the associated index it brings along with it) would be detrimental to performance.

    This type of table is typically replicated offline to a copy with indexes.

    Of course this isn't really the sort of table you'd want to use an EJB to access anyway........
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  4. CMP bean without a primary key & all columns nullable[ Go to top ]

    Yes this is possible with an ejb, because the uniqueness of an object is maintained by the primary key class of the ejb.
    But i say that it would be a bad design.
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