NOTE in .NET framework

Generate PDF-417 2d barcode in .NET framework NOTE

NOTE
Create PDF417 In Visual Studio .NET
Using Barcode drawer for .NET framework Control to generate, create PDF 417 image in .NET applications.
www.OnBarcode.com
PDF 417 Decoder In Visual Studio .NET
Using Barcode reader for VS .NET Control to read, scan read, scan image in .NET applications.
www.OnBarcode.com
Test to find the best threshold for your system
Bar Code Generation In Visual Studio .NET
Using Barcode encoder for .NET framework Control to generate, create barcode image in .NET applications.
www.OnBarcode.com
Scan Barcode In Visual Studio .NET
Using Barcode recognizer for .NET Control to read, scan read, scan image in .NET applications.
www.OnBarcode.com
These thresholds for determining whether your system is suffering from external or internal fragmentation provide a guideline for determining when you should use either ALTER INDEX REORGANIZE or ALTER INDEX REBUILD. Because the actual thresholds can vary depending on your environment, you should perform tests to determine the best thresholds for your system.
PDF417 Generation In Visual C#
Using Barcode maker for .NET Control to generate, create PDF-417 2d barcode image in Visual Studio .NET applications.
www.OnBarcode.com
Draw PDF-417 2d Barcode In .NET Framework
Using Barcode creation for ASP.NET Control to generate, create PDF-417 2d barcode image in ASP.NET applications.
www.OnBarcode.com
Managing Index Fragmentation
Drawing PDF 417 In VB.NET
Using Barcode creation for VS .NET Control to generate, create PDF-417 2d barcode image in VS .NET applications.
www.OnBarcode.com
Creating Code 39 Full ASCII In .NET Framework
Using Barcode generation for .NET framework Control to generate, create Code39 image in VS .NET applications.
www.OnBarcode.com
If you determine that your indexes have external or internal fragmentation, you should execute either the ALTER INDEX REORGANIZE or ALTER INDEX REBUILD statements periodically to prevent index fragmentation from affecting query performance.
Making DataMatrix In .NET Framework
Using Barcode generator for VS .NET Control to generate, create Data Matrix image in Visual Studio .NET applications.
www.OnBarcode.com
QR Code ISO/IEC18004 Creation In .NET Framework
Using Barcode generation for Visual Studio .NET Control to generate, create QR image in .NET framework applications.
www.OnBarcode.com
ALTER INDEX REORGANIZE
Draw Matrix 2D Barcode In .NET
Using Barcode creation for VS .NET Control to generate, create Matrix Barcode image in VS .NET applications.
www.OnBarcode.com
Planet Creation In .NET
Using Barcode drawer for .NET Control to generate, create USPS PLANET Barcode image in Visual Studio .NET applications.
www.OnBarcode.com
Using ALTER INDEX REORGANIZE reorganizes an index. This statement defragments the leaf level of clustered and nonclustered indexes on tables and views by physically reordering the leaf-level pages to match the logical, left-to-right order of the leaf nodes while compacting the index pages. The level of page compaction is based on the existing fill factor value for the index. You can find the fill factor value in the sys.indexes catalog view.
QR Code Creation In C#
Using Barcode drawer for VS .NET Control to generate, create QR image in .NET applications.
www.OnBarcode.com
Decoding Data Matrix ECC200 In Java
Using Barcode reader for Java Control to read, scan read, scan image in Java applications.
www.OnBarcode.com
USE AdventureWorks; ALTER INDEX PK_Employee_EmployeeID ON HumanResources.Employee REORGANIZE;
Painting Barcode In None
Using Barcode printer for Font Control to generate, create bar code image in Font applications.
www.OnBarcode.com
Bar Code Creator In Java
Using Barcode creator for Java Control to generate, create bar code image in Java applications.
www.OnBarcode.com
MORE INFO
Printing EAN128 In Objective-C
Using Barcode printer for iPad Control to generate, create USS-128 image in iPad applications.
www.OnBarcode.com
Draw QR Code In Objective-C
Using Barcode encoder for iPad Control to generate, create QR Code JIS X 0510 image in iPad applications.
www.OnBarcode.com
Fill factor
EAN / UCC - 13 Maker In Java
Using Barcode maker for Android Control to generate, create UCC.EAN - 128 image in Android applications.
www.OnBarcode.com
Barcode Decoder In Visual C#
Using Barcode Control SDK for .NET framework Control to generate, create, read, scan barcode image in VS .NET applications.
www.OnBarcode.com
For information about fill factor, see 4, Creating Indexes, in this book and the topic sys.indexes (Transact-SQL) in SQL Server 2005 Books Online.
ALTER INDEX REBUILD
Using the ALTER INDEX REBUILD statement rebuilds an index. This statement removes both external and internal fragmentation by dropping and re-creating the index. This process removes external fragmentation by reordering the index rows in
Lesson 1: Managing Index Fragmentation
contiguous pages and removes internal fragmentation by compacting the pages based on the specified or existing fill factor setting.
USE AdventureWorks; ALTER INDEX PK_Employee_EmployeeID ON HumanResources.Employee REBUILD;
NOTE
Using the ALL option
By specifying the ALL option on the ALTER INDEX REBUILD statement, you can specify that all indexes on a table be dropped and re-created in a single transaction.
When rebuilding an index, you have the option of performing the index rebuild by using the ONLINE option. When this option is ON, the table and associated indexes are available for queries and data modification during the rebuild process. DBAs can perform concurrent online index operations on the same table only when performing the following index operations:
Creating multiple nonclustered indexes Reorganizing different indexes on the same table Reorganizing different indexes while rebuilding nonoverlapping indexes on the same table
Determining Which Statement to Execute
How do you know whether to execute ALTER INDEX REORGANIZE or ALTER INDEX REBUILD against user tables When your indexes are not heavily fragmented, you can reorganize indexes, which uses few system resources and runs automatically online. For heavily fragmented indexes, you probably need to rebuild the indexes. To help you determine which statement to use, periodically run a SELECT statement against the sys.dm_db_index_physical_stats DMF and use the following thresholds as a guideline for your decision:
Execute ALTER INDEX REORGANIZE to defragment indexes that fall under the following fragmentation thresholds: avg_page_space_used_in_percent < 75 and > 60 or avg_fragmentation_in_percent > 10 and < 15. Execute ALTER INDEX REBUILD to defragment indexes that fall under the following fragmentation thresholds: avg_page_space_used_in_percent < 60 or avg_fragmentation_in_percent > 15.
12
Using Transact-SQL to Manage Databases
Quick Check
What is external fragmentation External fragmentation is the condition in which the physical order of index pages does not match the logical order.
Quick Check Answer
PRACTICE
Using ALTER INDEX to Correct Index Fragmentation Levels
DBAs need to learn how to manage index fragmentation levels by using the ALTER INDEX REBUILD and ALTER INDEX REORGANIZE statements. The following two practices take you through the process of correcting index fragmentation levels by using these two statements.
Practice 1: Use ALTER INDEX REBUILD to Rebuild an Index
In this practice, you rebuild an index by using the ALTER INDEX REBUILD statement. 1. Start SSMS. 2. Connect to the instance containing the sample AdventureWorks database. 3. In Object Explorer, right-click the AdventureWorks database and choose New Query to open the Query Editor pane. 4. In the Query Editor pane, type in the following Transact-SQL statement to view cur rent fragmentation levels, rebuild t he indexes on t he HumanResources.Employee table, and view fragmentation levels after the rebuild:
USE AdventureWorks; --View the current fragmentation levels. SELECT index_id, avg_fragmentation_in_percent, avg_page_space_used_in_percent FROM sys.dm_db_index_physical_stats (DB_ID( AdventureWorks ), OBJECT_ID( HumanResources.Employee ),NULL, NULL, DETAILED ) WHERE index_id <> 0; --does not return information about heaps --Rebuild all indexes on the table. --Create the indexes with a fill factor of 90. --Allow the index operation to take place ONLINE ALTER INDEX ALL ON HumanResources.Employee REBUILD WITH (FILLFACTOR = 90, ONLINE = ON); --View the fragmentation levels after the index rebuilds. SELECT index_id, avg_fragmentation_in_percent, avg_page_space_used_in_percent FROM sys.dm_db_index_physical_stats (DB_ID( AdventureWorks ), OBJECT_ID( HumanResources.Employee ),NULL, NULL, DETAILED ) WHERE index_id <> 0; --does not return information about heaps
Copyright © OnBarcode.com . All rights reserved.