x002548's Blog

Not Just a Number - Brett Kaiser
posts - 89, comments - 586, trackbacks - 39

April 2004 Blog Posts

Deltas

It's all about the update... EDIT: 9/9/2004:  Well that wasn't much of an explanation.  What the hell are deltas.....is it a place in Mississippi where they have great music and food?  Well, yes....but deltas here are meant to describe a process, where by a database table has a set of data WITH a primary key, and a file is supplied daily with “updates“ (and I use that term loosely) that need to be applied to the table.  Both the file and the table do not have to have the same structure, number of columns, datatypes and/or sizes...but the MUST have a...

posted @ Friday, April 23, 2004 11:49 AM | Feedback (0) | Filed Under [ SQL Server ]

Reasons to not use SELECT * (and when to use it)

I'd like to expand this list with anyones comments.  Thanks!  And if anyone knows the M$ link that discusses how they optimized SELECT * for existance, I'd appreciate a linke.  Thamks again! Why you shouldn't 1. Effeciency: Only the data you need Reduces the amount of I/O that has to occur 2. Better use of indexes May use Index intersection or make use of covered indexes 3. Isolate code from Table object changesFor example, the following would through an error INSERT INTO myTable99(Col1, Col2, Col3,ect) SELECT * FROM myTable00 WHERE 4. I get a chuckle when Access developers say DELETE * FROM mytable99 'nough said 5. Increases network traffic, requires more...

posted @ Thursday, April 22, 2004 11:00 AM | Feedback (6) | Filed Under [ SQL Server ]

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