Resource Governor in SQL Server 2008 – Beware of catches

Resource governor is one of the best additions in SQL Server 2008. It gives you a real control on your environment as a DBA and can be very useful for better utilization of your database server resources. So far so good, but don’t just start using it without knowing how it actually restricts resource utilization.  Following are some points to remember for better utilization of this feature:

1. Normally, most of us assume that if we restricts a memory usage for a user A upto 10% only then he will never be able to utilize more than 10% of server in any case. Right? Wrong. Actually, Resource governer only restricts user to utilize not more than 10% if it feels that remaining memory is not available but if memory is available and there are no pending workload then it will allow the user to use more than its allowed quota of 10%. This is there to optimize the utilization of memory and avoids wastage of resources. But it can have worse effects also because if User A fires it query before other users then server will start utilizing all the available memory and all other users which came afterwards will suffer the consequences.
2. Please note that Resource Governor is for database engine not for other services in SQL Server 2008. It means you can not control usage of Reporting Services, Analysis Services or Integration Services.
3. If you have multiple instances running on same machine then you can not use Resource Governor to manage load between these instances.

Keeping these points in your mind will help you to better understand how to use resource governor and what to expect. It is one of the best tools to manage your load and highly recommended but make sure you know the pros and cons of it.

How to copy query results With column headers?

It is a very common practice that sometime you need to copy the query results from SQL Server Management Studio (SSMS) results tab to excel or any other application. The problem normally we face is that it does copy column headers and you have to write the column headers by your self. Here is the quick tip to enable column headers copying.

1. In SSMS, open Tools menu and click Options
2. Expand Query Results node and click Results to Grid
3. Check Include column headers when copying or saving the results. Your screen will look similar to following:



4. Click Save to save your settings.

Now, whenever you will copy the query results, column headers will be copied too.

Enjoy!

Deleting ununsed primary keys

Sometimes we need to make sure that all keys in the primary key table has atleast one corresponding row in child table or in other words every key has been used atleast once as a foreign key. This is a typical scenario we face during data import where data integrity can not be guarnteed 100% due to various reason. Following script demonstrate a simple technique to delete all those rows in the master table which are not used in child table.

Use tempdb;

/* Create sample tables and insert sample data */

Create table tblMaster

(

masterId int,

masterName varchar(50)

)

Go

Create table tblChild

(

childId int NOT NULL IDENTITY (1, 1),

masterId int,

childName varchar(50)

)

Go

Insert into tblMaster (masterId,masterName) values (1,‘Master 1′);

Insert into tblMaster (masterId,masterName) values (2,‘Master 2′);

Insert into tblMaster (masterId,masterName) values (3,‘Master 3′);

Insert into tblMaster (masterId,masterName) values (4,‘Master 4′);

Go

Insert into tblChild (masterId,childName) values (1,‘Child 1′);

Insert into tblChild (masterId,childName) values (1,‘Child 2′);

Insert into tblChild (masterId,childName) values (1,‘Child 3′);

Insert into tblChild (masterId,childName) values (2,‘Child 4′);

Go

/* Master table before deletion */

Select * from tblMaster

Go

/* Delete unused rows */

Delete tblMaster

where

not exists

(

Select masterId

from tblChild

where

tblChild.masterId=tblMaster.masterId

)

Go

/* Master table after deletion */

Select * from tblMaster

Go

/* Clean up */

drop table tblMaster;

Go

drop table tblChild;

Go

Welcome to SQL Server 2008

Finally, wait is over and just one day before start of 2008 Olympic, Microsoft has released SQL Server 2008. It is a big day as many of us were waiting for the final release to start taking architectural decision based on new technologies offered by SQL Server 2008. The 180 day trial version is available here
To start with, I will recommend to watch following videos covering disfferent aspect of technologies used in SQL Server 2008
SQL Server 2008 Demos and Videos
You can also check these Web Casts

In my next articles, I will try to cover some fundamental technological advancements in this version of SQL Server 2008.