08 | Retrieving SQL Server Metadata and Improving Query Performance

Querying Microsoft SQL Server 2012 Jump Start

05 | SET Operators, Windows Functions, and Grouping

SET operators, Windows functions, GROUPING sets (PIVOT, UNPIVOT, CUBE, ROLLUP)

06 | Modifying Data INSERT, UPDATE, and DELETE statements, use of defaults, constraints, and triggers, OUTPUT

07 | Programming with T-SQL Using T-SQL programming elements, implementing error handling, understanding and implementing transactions

08 | Retrieving SQL Server Metadata and Improving Query PerformanceQuerying system catalogs and dynamic management views, creating and executing stored procedures, improving SQL

Server query performance

--Pre-filtered to exclude system objectsSELECT name, object_id, schema_id, type, type_descFROM sys.tables;

--Includes system and user objectsSELECT name, object_id, schema_id, type, type_descFROM sys.objects;

Information schema views

SELECT TABLE_CATALOG, TABLE_SCHEMA, TABLE_NAME, TABLE_TYPE

FROM INFORMATION_SCHEMA.TABLES;

SELECT VIEW_CATALOG, VIEW_SCHEMA, VIEW_NAME,TABLE_CATALOG, TABLE_SCHEMA, TABLE_NAME,COLUMN_NAME

FROM INFORMATION_SCHEMA.VIEW_COLUMN_USAGE;

SELECT VIEW_CATALOG, VIEW_SCHEMA, VIEW_NAME,TABLE_CATALOG, TABLE_SCHEMA, TABLE_NAME,COLUMN_NAME

FROM INFORMATION_SCHEMA.VIEW_COLUMN_USAGEWHERE COLUMN_NAME = BusinessEntityID

SELECT @@VERSION AS SQL_Version;

SELECT SERVERPROPERTY('ProductVersion') AS version;

SELECT SERVERPROPERTY('Collation') AS collation;

SELECT session_id, login_time, program_nameFROM sys.dm_exec_sessionsWHERE is_user_process = 1;

SELECT referencing_schema_name,referencing_entity_name,referencing_class_desc

FROM sys.dm_sql_referencing_entities('Sales.SalesOrderHeader', 'OBJECT');

GO

Naming pattern Description

db Database-related information

exec Query execution-related information

io I/O statistics

os SQL Server Operating System (SQLOS) information

tran Transaction-related information

--no parameters so lists all databaseEXEC sys.sp_databases;

--single parameter of name of table EXEC sys.sp_help N'Sales.Customer';

--multiple named parametersEXEC sys.sp_tables

@table_name = '%',@table_owner = N'Sales';

Name Description

sp_databases Lists databases in an instance of SQL Server

sp_tables Returns a list of tables or views, except synonyms

sp_columns Returns column information for the specified objects

--This example uses EXEC, includes the sys schema name, --and passes the table name as a named Unicode parameter --to a procedure accepting an NVARCHAR(776)--input parameter.EXEC sys.sp_help @objname = N'Sales.Customer';

CREATE PROCEDURE (

CREATE PROCEDURE Production.ProdsByProductLine(@numrows AS int, @ProdLine AS nchar)ASSELECT TOP(@numrows) ProductID,

Name, ListPriceFROM Production.ProductWHERE ProductLine = @ProdLine;

--Retrieve top 50 products with product line = MEXEC Production.ProdsByProductLine 50, M

Table scan: SQL Server reads all table rows

Index seek/scan: SQL Server uses indexes to find rows

Viewing graphical execution plans

Display Estimated Execution Plan

Include Actual Execution Plan

SET STATISTICS TIME ON;

SET STATISTICS IO ON;

CREATE PROCEDURE Production.ProdsByProductLine(@numrows AS int, @ProdLine AS nchar)ASSELECT TOP(@numrows) ProductID,

Name, ListPriceFROM Production.ProductWHERE ProductLine = @ProdLine;

--Retrieve top 50 products with product line = MEXEC Production.ProdsByProductLine 50, M

Writing well-performing queries will improve your SQL Server performance.

Improvements can be made by only retrieving the data you need which

means specify the exact columns you want returned instead of using *, and

also use the WHERE clause to return only the rows you need

Be sure to understand the benefits of indexing and create indexes that

support filters, joins, and ordering. If possible avoid using cursors and other

iterative approaches

Utilize execution plans to view information on which tables to access, which

indexes to use, what joins to perform. Execution plans provide a graphical

representation of the methods that SQL Server uses to execute a T-SQL

query. View these plans from right to left, and top to bottom and view

additional information by hovering your mouse over items displayed in the

plan.

2013 Microsoft Corporation. All rights reserved. Microsoft, Windows, Office, Azure, System Center, Dynamics and other product names are or may be registered trademarks and/or trademarks in the U.S. and/or other countries. The information herein is for informational purposes only and represents the current view of Microsoft Corporation as of the date of this presentation. Because Microsoft must respond to changing market conditions, it should not be interpreted to be a commitment on the part of Microsoft, and Microsoft cannot guarantee the accuracy of any information provided after the date of this presentation. MICROSOFT MAKES NO WARRANTIES, EXPRESS, IMPLIED OR STATUTORY, AS TO THE INFORMATION IN THIS PRESENTATION.