qr code generator c# Partitions Available with the PF Partition Function in C#

Generating QR-Code in C# Partitions Available with the PF Partition Function

tabLe 6-10 Partitions Available with the PF Partition Function
QR Code Generator In Visual C#
Using Barcode maker for .NET framework Control to generate, create QR Code 2d barcode image in .NET framework applications.
www.OnBarcode.com
Scanning QR Code In C#
Using Barcode reader for VS .NET Control to read, scan read, scan image in Visual Studio .NET applications.
www.OnBarcode.com
PaRtitiOn nUMbeR
Bar Code Encoder In C#
Using Barcode creation for .NET framework Control to generate, create bar code image in VS .NET applications.
www.OnBarcode.com
Bar Code Scanner In Visual C#
Using Barcode reader for .NET framework Control to read, scan read, scan image in .NET framework applications.
www.OnBarcode.com
PaRtitiOn RanGe
QR Code Printer In .NET
Using Barcode generator for ASP.NET Control to generate, create QR Code ISO/IEC18004 image in ASP.NET applications.
www.OnBarcode.com
Creating QR Code In Visual Studio .NET
Using Barcode drawer for .NET Control to generate, create QR image in Visual Studio .NET applications.
www.OnBarcode.com
1 2 3 4
Making Denso QR Bar Code In Visual Basic .NET
Using Barcode creation for .NET framework Control to generate, create Quick Response Code image in VS .NET applications.
www.OnBarcode.com
Paint PDF-417 2d Barcode In C#.NET
Using Barcode maker for .NET framework Control to generate, create PDF417 image in Visual Studio .NET applications.
www.OnBarcode.com
<= 10 > 10 AND <= 20 > 20 AND <= 30 > 30
Paint Barcode In C#
Using Barcode creator for Visual Studio .NET Control to generate, create barcode image in VS .NET applications.
www.OnBarcode.com
Paint EAN13 In Visual C#
Using Barcode generation for VS .NET Control to generate, create EAN13 image in .NET applications.
www.OnBarcode.com
Now consider the following code, which creates virtually the same partition function but defined as RIGHT instead of LEFT. The resulting partitions are shown in Table 6-11:
Printing UCC - 12 In Visual C#
Using Barcode generator for Visual Studio .NET Control to generate, create UPC-A Supplement 5 image in Visual Studio .NET applications.
www.OnBarcode.com
Identcode Generation In Visual C#.NET
Using Barcode generator for VS .NET Control to generate, create Identcode image in .NET applications.
www.OnBarcode.com
CREATE PARTITION FUNCTION pf (INT) AS RANGE RIGHT FOR VALUES (10, 20, 30);
Data Matrix 2d Barcode Decoder In VB.NET
Using Barcode scanner for .NET framework Control to read, scan read, scan image in .NET framework applications.
www.OnBarcode.com
Draw Code 128 Code Set B In None
Using Barcode creator for Font Control to generate, create ANSI/AIM Code 128 image in Font applications.
www.OnBarcode.com
tabLe 6-11 Partitions Available with the PF Partition Function
Code 39 Extended Creation In None
Using Barcode creator for Word Control to generate, create ANSI/AIM Code 39 image in Microsoft Word applications.
www.OnBarcode.com
QR-Code Decoder In VB.NET
Using Barcode scanner for VS .NET Control to read, scan read, scan image in VS .NET applications.
www.OnBarcode.com
PaRtitiOn nUMbeR
Decoding PDF 417 In None
Using Barcode recognizer for Software Control to read, scan read, scan image in Software applications.
www.OnBarcode.com
Code 128 Code Set B Recognizer In .NET Framework
Using Barcode reader for .NET framework Control to read, scan read, scan image in VS .NET applications.
www.OnBarcode.com
PaRtitiOn RanGe
Creating 2D Barcode In Visual Basic .NET
Using Barcode printer for .NET Control to generate, create Matrix 2D Barcode image in .NET applications.
www.OnBarcode.com
Data Matrix 2d Barcode Creator In Java
Using Barcode generation for BIRT reports Control to generate, create ECC200 image in Eclipse BIRT applications.
www.OnBarcode.com
1 2 3 4
< 10 >= 10 AND < 20 >= 20 AND < 30 >= 30
Lesson 2: Creating Indexes
Partition Schemes
You define a partition function by using the CREATE PARTITION SCHEME statement. The partition scheme is a simple map between partitions for a particular partition and file groups. The reason for using different file groups for different partitions is typically to be able to store different parts of a table on different types of storage devices; you might want to store older data on slower but cheaper devices and new data on faster but more expensive devices. The following example creates a partition scheme that maps each of the partitions defined in Table 6-11 to its own file group; as you can see, the same file group can be used for multiple partitions:
CREATE PARTITION SCHEME PS AS PARTITION PF TO (FG1, FG2, FG1, FG2);
As another example, the statement shown here creates a partition scheme mapping all partitions to the primary file group:
CREATE PARTITION SCHEME PS AS PARTITION PF ALL TO ([PRIMARY]);
Creating the Partitioned Table
After you have created the partition function and partition scheme, you can create tables and indexes on the partition scheme using the ON clause of the CREATE TABLE and CREATE INDEX statements. Even though you can have a table on one partition scheme and its indexes on different partition schemes (or one on a partition scheme and one not), it is recommended that they all be created on the same partition scheme to support adding and removing partitions as needed, without having to shut down any applications. A table with all indexes defined on the same partition scheme is said to have aligned partitions. Nonunique, nonclustered indexes are aligned automatically with the table s partition scheme when created; that is, you don t even need to specify the ON clause for the CREATE INDEX statement. For unique indexes, however, you must include the partitioning column in the index key to make it aligned with the table. This typically defeats the purpose of having a unique index. For example, if you want to add a unique index on the SSN column in a table partitioned over the ID column, you have to make it a composite index over both SSN and ID to align it. You typically must have any unique index defined as nonaligned; and if you need to add or remove a partition, you must drop the nonaligned index, add or remove the partition, and then re-create the nonaligned index. Doesn t doing all this defeat the purpose of the partitioning Not really if you have five aligned indexes and one nonaligned, you need only re-create the nonaligned index, whereas without partitioning, you potentially have to re-create all six indexes. Now let s look at an example of using partitioning to improve import performance. The following batch creates a partition function and partition scheme, as well as a table and a nonclustered index defined on the partition scheme. After the objects are created, an INSERT statement is used to populate the table with an initial 19,185 rows. Note that even though the CREATE INDEX statement doesn t use the ON clause to specify the partition scheme, the
238 CHAPTER 6 Techniques to Improve Query Performance
index is created on the partition scheme. The last part of the script is a query against the sys.partitions catalog view, which returns the 8 partitions created by the script: 4 for the table (heap, index_id = 0) and 4 for the nonclustered index (index_id = 2):
USE AdventureWorks;
CREATE PARTITION FUNCTION PFCustomerID (INT) AS RANGE LEFT FOR VALUES (5000, 10000, 15000);
CREATE PARTITION SCHEME PSCustomerID AS PARTITION PFCustomerID ALL TO ([PRIMARY]);
CREATE TABLE Test.CustomersPartitioned ( CustomerID INT IDENTITY NOT NULL ,AccountNumber VARCHAR(50) NOT NULL ,ModifiedDate DATETIME2 NOT NULL ) ON PSCustomerID (CustomerID);
CREATE NONCLUSTERED INDEX AccountNumberIdx ON Test.CustomersPartitioned (AccountNumber);
INSERT Test.CustomersPartitioned (AccountNumber, ModifiedDate) SELECT AccountNumber, ModifiedDate FROM Sales.Customer;
SELECT index_id, partition_number, rows FROM sys.partitions WHERE object_id = OBJECT_ID('Test.CustomersPartitioned') ORDER BY index_id, partition_number;
Here are the results of the query against the sys.partitions catalog view:
index_id partition_number rows ----------- ---------------- -------------------0 0 0 0 2 2 2 2 1 2 3 4 1 2 3 4 5000 5000 5000 4185 5000 5000 5000 4185
To import data into the Test.CustomersPartitioned table by adding a new partition, you need to define the new partition. To do that, you need to find the next divider value for the partition function and add it to the partition function. The following query finds the next divider for the PFCustomerID partition function:
SELECT MAX(CustomerID) AS MaxCustomerID FROM Test.CustomersPartitioned;
Copyright © OnBarcode.com . All rights reserved.