Usage of distributed partitioned view in .NET framework

Creation DataMatrix in .NET framework Usage of distributed partitioned view

Usage of distributed partitioned view
Data Matrix 2d Barcode Decoder In VS .NET
Using Barcode Control SDK for .NET Control to generate, create, read, scan barcode image in VS .NET applications.
Data Matrix Maker In .NET Framework
Using Barcode generation for .NET Control to generate, create DataMatrix image in Visual Studio .NET applications.
C h a p t e r 8 : S p e c i a l Ty p e s o f P r o c e d u r e s
Scan Data Matrix In .NET Framework
Using Barcode scanner for .NET Control to read, scan read, scan image in .NET framework applications.
Printing Barcode In VS .NET
Using Barcode creation for VS .NET Control to generate, create bar code image in VS .NET applications.
Figure 8-15
Decoding Barcode In Visual Studio .NET
Using Barcode reader for .NET framework Control to read, scan read, scan image in VS .NET applications.
Data Matrix 2d Barcode Generation In C#
Using Barcode creator for Visual Studio .NET Control to generate, create ECC200 image in Visual Studio .NET applications.
Distributed partitioned view connects to tables on all member servers
Draw Data Matrix ECC200 In .NET
Using Barcode maker for ASP.NET Control to generate, create Data Matrix image in ASP.NET applications.
Data Matrix Drawer In VB.NET
Using Barcode generator for .NET Control to generate, create DataMatrix image in VS .NET applications.
Execution Plans of Distributed Partitioned Views
GS1 DataBar Expanded Printer In Visual Studio .NET
Using Barcode drawer for Visual Studio .NET Control to generate, create GS1 RSS image in Visual Studio .NET applications.
Data Matrix ECC200 Drawer In Visual Studio .NET
Using Barcode generator for .NET Control to generate, create Data Matrix ECC200 image in VS .NET applications.
If the query contains a criterion based on the partitioning key, SQL Server evaluates which servers contain matching data and executes the query against them only:
Painting Bar Code In Visual Studio .NET
Using Barcode encoder for .NET framework Control to generate, create barcode image in VS .NET applications.
RM4SCC Creator In .NET
Using Barcode drawer for Visual Studio .NET Control to generate, create British Royal Mail 4-State Customer Barcode image in VS .NET applications.
set statistics Profile ON select * from vInventoryDist where Country = 'UK' Rows Executes StmtText ---- -------- -------------------------------------------------------154 1 SELECT * FROM [vInventoryDist] WHERE [Country]=@1 154 1 |--Compute Scalar(DEFINE:([InventoryWorld].[Inventoryid 154 1 |--Clustered Idx Seek(OBJ:([Asset].[dbo].[InventoryWo
Painting ANSI/AIM Code 39 In .NET
Using Barcode drawer for ASP.NET Control to generate, create Code 3/9 image in ASP.NET applications.
Draw GS1 - 12 In .NET Framework
Using Barcode creation for ASP.NET Control to generate, create UPC Symbol image in ASP.NET applications.
SQL Server 2000 Stored Procedure & XML Programming
Create UCC-128 In Java
Using Barcode printer for Java Control to generate, create EAN128 image in Java applications.
Making GTIN - 13 In None
Using Barcode creator for Online Control to generate, create EAN 13 image in Online applications.
The profile shows that the query was executed on the local server. In a case in which the data resides on another server, the profile would look like this:
Code 39 Extended Recognizer In Visual C#
Using Barcode recognizer for Visual Studio .NET Control to read, scan read, scan image in .NET applications.
Scan Data Matrix 2d Barcode In .NET Framework
Using Barcode scanner for .NET framework Control to read, scan read, scan image in .NET framework applications.
set statistics Profile ON select * from vInventoryDist where Country = 'CANADA' Rows Executes StmtText ---- -------- -------------------------------------------------------872 1 SELECT * FROM [vInventoryDist] WHERE [Country]=@1 872 1 |--Compute Scalar(DEFINE:([(local)\CANADA].[Asset].[d 872 1 |--Remote Query(SOURCE:((local)\CANADA), QUERY:(SE
Read Barcode In .NET
Using Barcode reader for .NET Control to read, scan read, scan image in .NET applications.
Encoding Bar Code In Objective-C
Using Barcode printer for iPad Control to generate, create bar code image in iPad applications.
Figure 8-16 shows how the view will route the query to the remote server. It is necessary to create partitioned views on two other servers with identical names. In that way, an application can get the data through the view on any of the servers. The views will reroute the query to the server that contains the data that is needed (see Figure 8-17).
Figure 8-16
Distributed partitioned view routes the query to the remote server
C h a p t e r 8 : S p e c i a l Ty p e s o f P r o c e d u r e s
Figure 8-17
Data-dependent routing
The system will achieve better performance if the partitioned view does not have to perform query routing that is, if the application knows which server contains the data needed and therefore sends the query to the appropriate server. This technique is often called data-dependent routing.
NOTE
If the application is that intelligent, you might wonder why you need distributed partitioned views. Well, not all queries can be served from a single server. Some queries require data that is located on more than one server, and a distributed partitioned view would give you access to it.
The selection of a partitioning key and implementation of a Check constraint have a critical impact on the performance of the system. You would have seen this fact
SQL Server 2000 Stored Procedure & XML Programming
demonstrated had you implemented the partitioning key using the nonoptimizable argument (an argument that leads the optimizer to create an execution plan that will ignore indexes):
... CONSTRAINT [chkInventoryWorld] CHECK ([Country] <>'USA' and [Country] <>'Canada')) ) ON [PRIMARY]
In such a case, SQL Server cannot determine where data is located and the query will always be routed to the World server as well:
Rows Executes StmtText ---- -------- -------------------------------------------------------872 1 SELECT * FROM [vInventoryDist] WHERE [Country]=@1 872 1 |--Concatenation 872 1 |--Remote Query(SOURCE:((local)\CANADA), QUERY:(SELECT 0 1 |--Clustered Idx Seek(OBJ:(Asset.dbo.InventoryWorld.P
As you can see, the query was executed unnecessarily on one of the servers no records were returned. SQL Server compares Check constraints with the partition key ranges specified in the Where clause and builds the execution plan accordingly. You might think that SQL Server won t do such a good job when stored procedures are used against distributed partitioned views. It is true that SQL Server does not know which parameter will be specified in the stored procedure, and therefore it creates an execution plan that runs the query against all servers. However, the plan will have dynamic filters that serve as conditional logic and execute only the queries that are needed. To demonstrate, I will create a stored procedure that references the view:
CREATE PROCEDURE prInventoryList @chvCountry varchar(50) AS SELECT * FROM vInventoryDist WHERE Country = @chvCountry
I will now execute it so that you can review the profile:
set statistics Profile ON exec prInventoryList 'CANADA'
C h a p t e r 8 : S p e c i a l Ty p e s o f P r o c e d u r e s
The execution plan will contain queries against all tables:
Rows Executes StmtText ---- -------- ----------------------------------------------------872 1 select * from vInventoryDist where Country = @chvCoun 872 1 |--Concatenation 872 1 | |--Clustered Index Seek(OBJECT:([Asset].[dbo].[ 0 1 |--Filter(WHERE:(STARTUP EXPR([@chvCountry]='USA'))) 0 0 | |--Remote Query(SOURCE:(.\USA), QUERY:(SELECT C 0 1 |--Filter(WHERE:(STARTUP EXPR([@chvCountry]='Ireland 0 0 |--Remote Query(SOURCE:(.\World), QUERY:(SELECT
But two of these queries are not executed (as you can see in the Executes column). Figure 8-18 shows a graphical representation of the execution plan with dynamic filters.
Figure 8-18
Copyright © OnBarcode.com . All rights reserved.