Updating multiple tables sql server
We’ll also consider the potential pitfalls of which you need to be aware before deciding to implement an indexed view. Unfortunately, however, applications grow more complex as the users demand new features, and so the accompanying queries grow more complex also.We don’t always have time to rewrite a query completely, or may not even know a better way to write it. When we encapsulate complex multi-table query logic in a view, any application that needs that data is then able to issue a much simpler query against the view, rather than a complex multi- permissions on the view, rather than the underlying tables, and use the view to restrict the columns and rows that are accessible to the user.Figure 3 We see the exact same execution plan, output, and query cost if we run the query in Listing 1 again.Although the use of the view made writing the query easier, it had no impact on query performance.Indexed views can be a powerful tool, but they are not a ‘free lunch’ and we need to use them with care.Once we create an indexed view, every time we modify data in the underlying tables then not only must SQL Server maintain the index entries on those tables, but also the index entries on the view. In addition, they also have the potential to cause other issues.In other words, when we query a simple view, the optimizer still has to access all of the underlying tables and perform the necessary s and aggregations.It derives cardinality estimations, and hence the query plan, from statistics associated with those tables.
Now, each application simply has to run a much simpler query referencing the view, as shown in Listing 3.
There is an article about this project at code project: there is the second article also at code project: ok, I have to admit that I got bored so I just want to make something.
It looks like I am reinventing a wheel(duplicating part of SQL Server Management Studio? I address something here that do not exist in SQL Server Management Studio at all, at least not in 2012RC0.
Target Step 1: a real monitor, keep tracking sql server actitivities(sql execution, cpu consumption, disk space etc), alert on customized notifications. Performance Graph Monitor Multiple Servers / Databases Popup/Dock Performance Graph 2.
Step 2: support oracle/mysql/firebird/postgresql etc. Step 3: accessible on any client (including mobile phones).
Any aggregations defined by the indexed view are now pre-computed, and any joins pre-joined, so the engine no longer has to do this work at execution time.