Computed columns or store
I need a couple of computed columns that contain count totals (indexed columns). Do you think it is better to use a computed column in a view or add extra columns to the table that will store the totals? Adding extra columns would probably mean us开发者_JAVA百科ing triggers to keep the count totals correct.
DB is MS SQL 2008 R2.
You can use a indexed view to get the performance of stored columns at no maintenance effort.
It depends.
If the tables change a lot but you rarely need the counts, a view is better. The question "view vs. computed columns" is one of DB design. If you can't change the original table or the DBMS doesn't support computed columns, use a view. If you can change the table definition, computed columns can be better but they also clutter the definition and make select *
slower if you don't always need this data.
If the table rarely changes but you need those numbers a lot, use extra columns with triggers to avoid performance problems.
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