Possibly some people will have a problem with the suggestion of prototyping a BI solution. Agile methods are increasingly what's expected of BI projects. Agile emphasises iterative delivery rather than...

emiranda 59653 (4/2/2014)

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I'm not too sure how useful they are for ETL unless doing auditing as by their nature, surrogate keys won't exist on source systems, but then again I'm...

Surrogate keys can be very useful for some ETL operations, especially for updates and deletes on the fact table. They can also be useful to support a partitioning or archiving...

awez1411 (3/18/2014)

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its properly work 3 times but at 4 or 5th time when i use bulk insert command all data are successfully inserted into table but it lost the sequence.

after...

azhar.iqbal499 (2/20/2014)

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Actually, when we define primary key on a table, data is stored in the physical order of primary key, We can't have two physical order in a table. This...

If there is a foreign key referencing your table then consider whether it's important for the date/time of the referencing row to correspond to the date/time range of your effectivedate....

Luis Cazares (2/12/2014)

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That's the difference of unique keys and primary keys. Primary keys will idenitfy a row within a table and they're essentially a preferred unique key. Unique keys will...

RonKyle (2/12/2014)

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My favourite example, a table of Marriages with exactly two attributes: Husband and Wife. Both attributes are candidate keys because clearly we don't want to allow the same person...

Jeff Moden (1/30/2014)

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By definition and by design and as the others have stated, you cannot have two Primary Keys on a table. If you try to create a second...

Lowell (12/4/2013)

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Maybe I'm reading your statement wrong, but i read "actually a foreign key can reference columns that aren't key columns at all" as though you are implying you can...

That's incorrect. It's...

QED. A...

Lynn Pettis (12/4/2013)

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Your example of marriages is flawed. It would be quite possible to have two couples where the husbands and/or the wives have the same names. If...

That depends on the methodology, the modelling notation used and the modeller's practice and intention. It also...

gautham.gn (12/2/2013)

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There is a restriction that we must have only one primary key per table. We can have composite primary key by defining primary key over 2 or more columns....