If all the columns are from a single table, you definitely should created a computed column that has the computation: that way, the definition is in only one place. ...[/code]
Otherwise, use CROSS APPLY, keeping the definition in only one place in the query. If the calculation is used in many queries, consider constructing an inline "row-valued" function.
“Write the query the simplest way. If through testing it becomes clear that the performance is inadequate, consider alternative query forms.” - Gail Shaw
For fast, accurate and documented assistance in answering your questions, please read this article
.Understanding and using APPLY, (I)
and (II) Paul White Hidden RBAR: Triangular Joins
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