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How does view help database performance?
Views make queries faster to write, but they don’t improve the underlying query performance. In short, if an indexed view can satisfy a query, then under certain circumstances, this can drastically reduce the amount of work that SQL Server needs to do to return the required data, and so improve query performance.
What is the advantage of using a view?
Views can provide advantages over tables: Views can represent a subset of the data contained in a table. Consequently, a view can limit the degree of exposure of the underlying tables to the outer world: a given user may have permission to query the view, while denied access to the rest of the base table.
Can somebody tell me what’overhead’is in my SQL database?
I’d define “too much overhead” as hunderds of megabytes of wasted space in a table. That’s purely a gut feeling, not based on any measurements. As long as you don’t optimize to get a few dozen megabytes back, especially if the table is 2GB.
Why do you create a view in a database?
You can create a view that only includes the columns they need access to and then grant them access on the view. A view is an encapsulation of a query. Queries that are turned into views tend to be complicated and as such saving them as a view for reuse can be advantageous.
Can a view be created with more than one table?
A view can be created that uses more than one table or other views with a SELECT clause of any complexity. In an indexed view definition, the SELECT statement must be a single table statement or a multitable JOIN with optional aggregation.
Why are database views not good for query performance?
The database’s optimizer may have more trouble creating a good query execution plan. So while views can be very good in terms of allowing more fine grained security and the like, they are not necessarily good for modularity. It depends on the RDBMS, but usually there isn’t optimization going on, and it’s just a convenient way to simplify queries.