SQL Facts: Indexes Limit Increased in SQL 2008

The limit of nonclustered indexes are increased from 249 to 999 in SQL Server 2008

SQL Administration: Dynamic Management Views

Introduction

The DMVs; newly introduced in SQL Server 2005 gives the database administrator information about the current state of the SQL Server machine. These values will help the administrator to diagnose problems and tune the server for optimal performance. DMVs are designed to be used instead of system tables and various other functions provided in SQL Server 2000. Here, we will see only about the frequently used DMVs.

Two types of dynamic management views:

a)   Server-scoped DMV: Stored in Master Database

b)   Database-scoped DMV: Specific to each database

Permission to Execute DMV [Security]

To query a server scoped DMV, the database user must have SELECT privilege on VIEW SERVER STATE and for database scoped DMV, the user must have SELECT privilege on VIEW DATABASE STATE.

• GRANT VIEW SERVER STATE to
• GRANT VIEW DATABASE STATE to

If you want to deny a user permission to query certain DMVs, you can use the DENY command to restrict access to a specific DMV.

Getting Started

All the DMVs exits in SYS schema and their names start with DM_. So when you need to query a DMV, you should prefix the view name with SYS. As an example, if you need to see the total physical memory of the SQL Server machine; then execute the below TSQL command:

SELECT 

(Physical_memory_in_bytes/1024.0)/1024.0 AS Physical_memory_in_Mb 

FROM 

sys.dm_os_sys_info

In this article, I will be explaining some of the DMVs which can be used frequently to understand the current behavior of SQL Server:

1. SQL Server related [Hardware Resources] DMV
2. Database related DMV
3. Index related DMV
4. Execution related DMV

1.   SQL Server Related DMV

This section details the DMVs associated with SQL Server system. SQL DMV is responsible to manage server level resources specific to a SQL Server instance.

This section covers DMVs related to OS, Disk and Memory.

a)   sys.dm_os_sys_info

b)   sys.dm_os_hosts

c)   sys.dm_os_schedulers

d)   sys.dm_io_pending_io_requests

e)   sys.dm_io_virtual_file_stats

f)    sys.dm_os_memory_clerks

g)   sys.dm_os_ring_buffers

a)   sys.dm_os_sys_info

This view returns the information about the SQL Server machine, available resources and the resource consumption.

This view returns information like the following:

1. CPU Count: Number of logical CPUs in the server
2. Hyperthread-ratio: Ratio of logical and physical CPUs
3. Physical_memory_in_bytes: Amount of physical memory available
4. Virtual_memory_in_bytes: Amount of virtual memory available
5. Bpool_commited: Committed physical memory in buffer pool
6. OS_Priority_class: Priority class for SQL Server process
7. Max_workers_thread: Maximum number of workers which can be created

b)   sys.dm_os_hosts

This view returns all the hosts registered with SQL Server 2005. This view also provides the resources used by each host.

1. Name: Name of the host registered
2. Type: Type of hosted component [SQL Native Interface/OLE DB/MSDART]
3. Active_tasks_count: Number active tasks host placed
4. Active_ios_count: I/O requests from host waiting

c)   sys.dm_os_schedulers

SQL Administration: Database and Execution Related DMVs:

sys.database_permissions: Contains information about all the permissions held by users and roles

sys.database_permissions: Contains information about all the permissions held by users and roles

sys.columns: Contains data about each column of an object that has columns, such as views or tables

sys.database_principals: Contains information about all database users and database roles

sys.index_columns: -- Index columns

List of Execution DMVs:

sys.dm_exec_background_job_queue

sys.dm_exec_cached_plans

sys.dm_exec_connections

sys.dm_exec_plan_attributes

sys.dm_exec_query_optimizer_info

sys.dm_exec_query_resource_semaphores

sys.dm_exec_requests

sys.dm_exec_sql_text

sys.dm_exec_xml_handles

sys.dm_exec_background_job_queue_stats

sys.dm_exec_cached_plan_dependent_objects

sys.dm_exec_cursors

sys.dm_exec_query_memory_grants

sys.dm_exec_query_plan

sys.dm_exec_query_stats

sys.dm_exec_sessions

References: MSDN

EnJoY!!!!...

CoOoOlLlL.....

SQL Programming: Calling the web service with parameterized query string (using OLE automation)

 

Say, we have a webservice which sends SMS, which should be called by passing the needed parameters thru SQL query. 

 

We can get use of OLE Automation Stored Procedures within SQL Server.

List of Stored Procedure we can use to achieve this:
sp_OACreate - Creates an instance of an OLE object

sp_OAMethod
- Calls a method of an OLE object.

sp_OADestroy
- Destroys a created OLE object
sp_OASetProperty
- Sets a property of an OLE object to a new value
sp_OAGetProperty
- Gets a property value of an OLE object.

sp_OAStop
- Stops the server-wide OLE Automation stored procedure execution environment

 

These stored procedures were disabled by default, and should be initiated manually from surface area configuration tool (Refer MSDN).administrator privileges were required to execute this stored procedures

 

In SQL 2008,there is no surface area configuration tool. It is integrated within the Facets option.(refer mssqltips)

 

Set these options to True for better execution.

• ClrIntegrationEnabled
• OleAutomationEnabled
• XPCmdShellEnabled

 
Sample Stored Procedure Query:

 
declare @sUrl varchar(4000),@param1 varchar(100),@param2 varchar(100),
@obj int,@response varchar(800),@MobileNo varchar(50),@MovieName varchar(50), @SmsId int

 
select @RowCount =
count(*)
from tbl_SMSAlertMovie where status is null
while (@RowCount > 0)
begin

select
top 1 @SmsId =SmsId, MobileNo=MobileNo,@MovieName=MovieName from tbl_SMSAlertMovie where status is null

 

set @sUrl =
'http://192.168.17.17:8080/webservice.aspx?'

set @param1='&MobileNo='+@MobileNo

set @param2='&Movie='+@MovieName

set @sUrl= @sUrl+@param1+@param2

    exec
sp_OACreate
'WinHttp.WinHttpRequest.5.1', @obj OUT

    exec
sp_OAMethod
@obj,
'Open',
NULL,
'GET', @sUrl, false

    exec
sp_OAMethod
@obj,
'send'

    exec
sp_OAGetProperty
@obj,
'responseText', @response OUT

    exec
sp_OADestroy
@obj

--    select @response [response] à use if you need to store result

 

update dbo.tbl_ SMSAlertMovie

set Status='Y' where SmsId=@SmsId

 

select @RowCount =
count(*)from tbl_SMSAlertMovie where status is null

end

 
EnJoY!!!!...

CoOoOlLlL.....