SQL Server Code,Tips and Tricks, Performance Tuning

Sunday, December 17, 2006

BadVista: The Worst FUD You Will Ever Read.... St. Ignucious Has Gone Wild

Richard Stallman (RMS, St. Ignucious ) is at it again. let's see what the site says:

The Free Software Foundation (FSF) today launched BadVista.org, a campaign
with a twofold mission of exposing the harms inflicted on computer users by the
new Microsoft Windows Vista and promoting free software alternatives that
respect users' security and privacy rights.
“Vista is an upsell masquerading
as an upgrade. It is an overall regression when you look at the most important
aspect of owning and using a computer: your control over what it does. Obviously
MS Windows is already proprietary and very restrictive, and well worth
rejecting. But the new 'features' in Vista are a Trojan Horse to smuggle in even
more restrictions. We'll be focusing attention on detailing how they work, how
to resist them, and why people should care”, said FSF program administrator John
Sullivan.

More interesting is the piece of garbage that they link to: 25 Shortcomings Of Vista

Here are some of the 'gems'

1. SMB2: Vista introduces a new variant of the SMB protocol called SMB2, which may pose problems for those connecting to non-Microsoft networks, such as Samba on Linux.
--Speculation and pure FUD

7. Five Versions: The array of Vista editions could prove to be three too many, and upgrades between versions remain an unknown.
8. Activation: The need to activate the product via the Web could prove to be a time-waster during mass deployments.
--Could prove? Could prove? Who writes this stuff? For mass deployments there is something called Key Management Service

Key Management Service
Your organization can host the Key Management Service (KMS) internally to automatically activate computers running Windows Vista. To use the KMS, you must have a minimum of 25 computers running Windows Vista that are connected together. Computers that have been activated through KMS will be required to reactivate by connecting to your organization's network at least every six months.

Currently the KMS software runs on a local computer running Windows Vista or the Microsoft Windows Server Code Name "Longhorn" operating system. In the future, it will run on the Microsoft Windows Server 2003 operating system.

9. Storage Space: With Vista taking as much as 10 Gbytes of hard drive space, big and fast hard drives will be a must.
--Last time I checked you can't really buy anything less than 100GB

10. Backup: See No. 9. Backing up desktops will take a great deal of space.
--So backup only your personal data.

18
Buried Controls
Many options and controls are further buried, requiring a half-dozen mouse clicks or more to get to. Network settings and display settings are offenders here.
--Some people said the same thing in WinXP, until they realized there is also a classic view. Vista has this classic view also.

19. Installation Can take hours on some systems. Upgrades are even slower.
--This is BS; it should not take more than 30 minutes unless you got a pirated copy on 1500 floppy discs

20. HHD Hybrid Hard Drives. These are potentially a huge performance booster, but there's little information and support is available (even though should be available).
--Since when is having an emerging technology that will boost performance a shortcoming?

#25:
WordPadAbility to open .doc files has been removed.
--Hahahahahaha who wrote this piece of crap. You either use Word or OpenOffice

The writer of this article is Frank J. Ohlhorst send him an email if you want to tell him what you think

Friday, December 15, 2006

Three Ways To Display Two Counts From a Table Side By Side

This question came up on tek-tips.

I want to count the CA and the UT states from the authors table and output this in different columns named CaCount and UtCount

CaCount UtCount
----------- -----------
15 2

How do you do such a thing? To display the following is very easy

state StateCount
----- -----------
CA 15
UT 2

You just do a count and group by

SELECT state,COUNT(*) AS StateCount
FROM authors
WHERE state in ('CA', 'UT')
GROUP BY state

How do we display them side by side? We can do this 3 different ways
1 stick the count in variables
2 run the count twice a s a separate query
3 sum with case

USE PUBS
GO

--stick the count in variables
DECLARE @UtCount INT
DECLARE @CaCount INT

SELECT @UtCount = COUNT(*) FROM authors WHERE state ='UT'
SELECT @CaCount = COUNT(*) FROM authors WHERE state ='CA'

SELECT @CaCount AS CaCount,@UtCount AS UtCount

--run the count twice as a separate query
SELECT (SELECT COUNT(*) FROM authors
WHERE state ='CA') AS CaCount,
(SELECT COUNT(*) FROM authors WHERE state ='UT') AS UtCount

--sum with case
SELECT SUM(CASE state WHEN 'CA' THEN 1 ELSE 0 END) AS CaCount,
SUM(CASE state WHEN 'UT' THEN 1 ELSE 0 END) AS UtCount
FROM authors

If you look at the execution plan then you will see that the best option is the third one (sum with case). The third option only queries the table once instead of twice like the other two solutions and will thus be twice as fast
So keep that in mind when you have to do such a query next time

[edit]
Oracle Version
jbjornson left the Oracle version in a comment; I decided to add it to the post. I don't know about the syntax coloring on Oracle/TOAD so you are getting a black and white only ;-(

--run the count twice as a separate query
SELECT CA.caCount, UT.UtCount
FROM (SELECT COUNT(*) as CaCount FROM authors) WHERE state ='CA') CA,
(SELECT COUNT(*) FROM authors WHERE state ='UT') UT

--sum with case
SELECT SUM(decode(state, 'CA', 1, 0)) AS CaCount,
SUM(decode(state, 'UT', 1, 0)) AS UtCount
FROM authors
[/edit]

Visual Studio 2005 Service Pack 1 (SP1) Released

Visual Studio 2005 Service Pack 1 (SP1) has been released. From the site:

Service Pack 1 addresses issues that were found through a combination of customers and partner feedback, as well as internal testing. The issues addressed range in severity from places where the syntax coloring was incorrect to customer reported crashes in various scenarios. In some areas, more than 50% of the bugs addressed were reported by customers through the MSDN Product Feedback Center and Microsoft Connect. Overall, Service Pack 1 offers customers improvements in responsiveness, stability and performance for Visual Studio 2005.

Through further advancement and feedback, Service Pack 1 also provides over 70 improvements for common development scenarios including:

New processor support (e.g., Core Duo) for code generation and profiling

Performance and scale improvements in Team Foundation Server

Team Foundation Server integration with Excel 2007 and Project 2007

Tool support for occasionally connected devices and SQL Server Compact Edition

Additional support for project file based Web applications

Windows Embedded 6.0 platform and tools support

Get it here

Wednesday, December 13, 2006

Index Build Strategy In SQL Server

The Tips, Tricks, and Advice from the SQL Server Query Processing Team blog has 3 really good posts about Index Build strategy in SQL Server. You should definitely read these to really understand how to implement that. Here are the links:
Index Build strategy in SQL Server - Part 1: offline, serial, no partitioning

Index Build strategy in SQL Server - Part 2: Offline, Parallel, No Partitioning

Index Build strategy in SQL Server - Part 2: Offline, Parallel, No Partitioning (Non stats plan (no histogram))

Problems With ROW_NUMBER() In A WHERE Clause

This is a question that came up today. A person had a query like this

USE AdventureWorks
GO

SELECT
ROW_NUMBER() OVER (ORDER BY addressline1) AS rowNum,
addressline1,
city
FROM person.address
WHERE rowNum > 3;

That gave the following error
Server: Msg 207, Level 16, State 1, Line 6
Invalid column name 'rowNum'.

What you have to do is use Common Table Expressions or use a subquery. Below are both methods.

--Subquery
SELECT * FROM ( SELECT
ROW_NUMBER() OVER (ORDER BY addressline1) AS rowNum,
addressline1,
city
FROM person.address) AS x
WHERE rowNum > 3;

--CTE
WITH x (rowNum,addressline1,
city) AS
(SELECT
ROW_NUMBER() OVER (ORDER BY addressline1) AS rowNum,
addressline1,
city
FROM person.address)

SELECT * FROM X
WHERE rowNum > 3;

Tuesday, December 12, 2006

SQL Server 2005 Practical Troubleshooting: The Database Engine Is Shipping!

Amazon is shipping SQL Server 2005 Practical Troubleshooting: The Database Engine. This is a must have for all SQL developers who run into any kind of problems with SQL Server 2005

For all of you who did not read my interview with the editor of this book Ken Henderson; you can find that here; Ken describes the target audience for the book the most important chapters for customers who have performance problems and much more

A sample chapter is available: Chapter 4 Procedure Cache Issues

About the book:
Paperback: 456 pages
Publisher: Addison-Wesley; 1ST edition
Language: English
ISBN: 0321447743

Contents
Preface
Chapter 1 Waiting and Blocking Issues
Chapter 2 Data Corruption and Recovery Issues
Chapter 3 Memory Issues
Chapter 4 Procedure Cache Issues
Chapter 5 Query Processor Issues
Chapter 6 Server Crashes and Other Critical Failures
Chapter 7 Service Broker Issues
Chapter 8 SQLOS and Scheduling Issues
Chapter 9 Tempdb Issues
Chapter 10 Clustering Issues
Index

Amazon Links:

Visual Studio Team Edition for Database Professionals links

By now you know that Visual Studio Team Edition for Database Professionals has been released. But do you know all the links to the newsgroup, documentation and download page? No? No problem here are the links:

Download Link
The product is available on the MSDN subscribers site, or you can download the trial version from he following URL :http://www.microsoft.com/downloads/details.aspx?FamilyId=7DE00386-893D-4142-A778-992B69D482AD&displaylang=en
For the trial version, you still need an installed copy of Visual Studio 2005 Team Suite which can be either a trial or a licensed version

Documentation
Team Edition for Database Professionals

Forum
Visual Studio Team System - Database Professionals

Visual Studio 2005 Team Edition for Database Professionals Site
Data Dude

Sunday, December 10, 2006

Wedding Anniversary

So here we are 9 years later. We are still married have 3 kids and bought our second home this year. So let me give you a little background of how I met my wife etc etc. I met my wife in a bar on the upper eastside in New York City.
I don’t remember the name of the bar but I do remember that we went to Elaine’s for a drink and also to a place named the Cowboy Bar. Fast forward to the wedding date; we got married twice first at City Hall on December 11th and then we did a church wedding on August 15th (the pictures are from that day) We did the December wedding separately so that we could start my Green Card process; my wife is a third generation Italian-American but I had Dutch and Croatian citizenships.

The wedding was 1 block from were we lived. My wife (to be) spent the night in a hotel with her sisters. The wedding started at 3; I was still rollerblading till 2:30 in Central Park. I took a shower got dressed and walked to the church (which was 1 block from my apartment)

5% of the wedding guests did jail time.
The reception was held at the Kitano Hotel which is located at 38th and Park Avenue. I did not have a huge wedding only 65 or so family members and some of our closest friends were invited. Out of those people there were 3 who did some jail time. One of them is Brendan who was the head of the NYC Hells Angels chapter at that time.

Another was brought by a friend and the last one was a friend of mine who did jail time because he beat up a cop. The Hells Angel did not dress up of course, if you look at the picture you can see me next to my wife. The other picture is me and my wife on the roof. The reception had 2 huge balconies; one was facing the Empire State Building and the other one was facing the Chrysler Building. The good thing when having your wedding at a hotel is that you can just walk to your room.

Honeymoon in Hawaii
So after the reception we had two days to get ready for the honeymoon. We did our shopping and on Monday night we went to China Club with out friend from Europe. China Club is the place to go to on Mondays; you can always spot some model or one of the Yankees or Knicks there. The next day we went to Maui and Kuai. I have said many times to my wife that I want to go back to Hawaii once before I die…. Maui and Kuai were beautiful places to spend your honeymoon; if you are into playing golf, surfing, hiking, snorkeling then there are lots of things to do here. Jurassic Park was shot in Kuai and once you arrive in Kuai you will recognize the green scenery right away

After the honeymoon
Once you are married don’t have kids right away; your live will change and you won’t be able to do anything for a while. So that is what we did; we waited 4 years to have kids. We visited Paris and Amsterdam and bought a house near Princeton before having our first son Christian. Then my wife became pregnant with twins and we had to sell our house and buy a bigger house. If owing you house is the American Dream then selling and buying your next house has to be the American Nightmare; what a stressful situation. After that ordeal I said that the next time I move will be in one of those 55+ community houses (I still have about 20 years to go). So today we live in Princeton and we have Catherine and Nicholas to keep us awake at night.

Traditions
My wife and I usually buy our Christmas tree on our anniversary. In the city we would pick up a Charlie Brown on 2nd avenue and 79th street; out here we go to the farm and chop down our own. Somehow my wife thinks it is also a tradition to watch Serendipity; if I have to watch a movie with Kate Beckingsale I prefer Underworld but hey you have to be nice on your anniversary….

BTW I still fit in my wedding suit, the tailor was wrong ;-(

Friday, December 08, 2006

Plan For The Day…Gone Wrong In a Big Way

It is my 9th year wedding anniversary this weekend so I took the day off today and below is a list of things I planned to do today

[ ] Get a Christmas tree at the farm
[ ] Go for breakfast with the whole family
[ ] Drop of a package at the post office
[X] Interview a person for a position at work
[ ] Enhance a Stored Procedure and close the item in BugTrax
[ ] Watch Serendipity (my wife insists)
[ ] Get haircuts
[X] Cover the furniture in the garden

As you can see I managed to accomplish two things only so far. What happened? My son got sick and had a high fever and threw up this morning; that eliminated the first 3 items right away. I managed to do the phone interview because it was a reversed phone interview (the candidate was at the office and I interviewed him from home over the phone)
Forget about the haircuts (I rescheduled for tomorrow); where do I leave our 3 kids?
So that leaves me with watching Serendipity tonight ;-(

Anyway I will post something about my wedding this weekend. Believe it or not 5% of the people that came to my wedding did jail time; one of them was the head of the NYC Hells Angels chapter( I will also post some pictures this weekend)

Oh you wanted some SQL material? No problem this will keep you busy for a while ;-)

Log Buffer #21: A Carnival of the Vanities for DBAs
Log Buffer #22: A Carnival of the Vanities for DBAs

Thursday, December 07, 2006

Get The Domain Name Of Your SQL Server Machine

How do you get the domain name that your SQL Server machine belongs to with T-SQL code?

You can use the undocumented procedure xp_regread; I have tested this on SQL Server 2005 and on SQL Server 2000.
Be advised that since this is an undocumented procedure that it might not be available in the future or it might be changed either because of a service pack or a hot fix. Don't use it as production code!

Here is how to do this

DECLARE @chvDomainName NVARCHAR(100)
EXEC master.dbo.xp_regread 'HKEY_LOCAL_MACHINE',
'SOFTWARE\Microsoft\Windows NT\CurrentVersion\Winlogon',
N'CachePrimaryDomain',@chvDomainName OUTPUT

SELECT @chvDomainName AS DomainName

Monday, December 04, 2006

Visual Studio 2005 Team Edition for Database Professionals Released to Manufacturing

On Friday 1st December 2006 the development team officially announced that Data Dude was done and was being released to manufacturing. It should be available for download to MSDN subscribers on December 7th 2006 and generally available for purchase on January 1st 2007.

This release marks the end of the first leg in a very exciting journey to revolutionize the ALM space and finally bring the database into the application lifecycle.

You can find more info about Data Dude here: Visual Studio Team Edition for Database Professionals

Sunday, December 03, 2006

Tuesday, November 28, 2006

Use SCHEMABINDING In Views To Protect Against Alteration Or Dropping Of Tables

My post from last night triggered something in me to write a little bit about SCHEMABINDING.
If you create a view and someone drops one of the tables that the view is dependent on then the view will fail. How can you protect yourself against that? You can use WITH SCHEMABINDING. Here is how you use it:

Let's first create some tables and the view

CREATE TABLE dbo.Test1 (ID INT, SomeName VARCHAR(49))
CREATE TABLE dbo.Test2 (ID2 INT, SomeOtherName VARCHAR(49))

INSERT dbo.Test1 VALUES 1,'Name1')
INSERT dbo.Test1 VALUES( 2,'Name2')
INSERT dbo.Test2 VALUES( 1,'OtherName1')
INSERT dbo.Test2 VALUES( 2,'OtherName2')

CREATE VIEW dbo.TestTables
AS
SELECT ID,SomeName, ID2,SomeOtherName
FROM dbo.Test1 t1
JOIN dbo.Test2 t2 on t1.ID =t2.ID2

--SELECT from the view and everything is fine
SELECT *
FROM dbo.TestTables

-- Drop table test2
DROP TABLE dbo.Test2

--Let's do the select again
SELECT * FROM dbo.TestTables

--And this is the error message that we get back
Server: Msg 208, Level 16, State 1, Procedure TestTables, Line 3
Invalid object name 'Test2'.
Server: Msg 4413, Level 16, State 1, Line 1
Could not use view or function 'TestTables' because of binding errors.

--Let's create the Test2 table again
CREATE TABLE dbo.Test2 (ID2 INT, SomeOtherName VARCHAR(49))

INSERT dbo.Test2 VALUES( 1,'OtherName1')
INSERT dbo.Test2 VALUES( 2,'OtherName2')

--Now let's alter the view and we will use SCHEMABINDING
ALTER VIEW dbo.TestTables WITH SCHEMABINDING
AS
SELECT ID,SomeName, ID2,SomeOtherName
FROM dbo.Test1 t1
JOIN dbo.Test2 t2 on t1.ID =t2.ID2

--Try dropping the Test2 table again
DROP TABLE dbo.Test2

--And here is the message
Server: Msg 3729, Level 16, State 1, Line 1
Cannot DROP TABLE 'dbo.Test2' because it is being referenced by object 'TestTables'.

--Let's try altering the table by adding a column
ALTER TABLE dbo.Test2 ADD Col3 INT

-- That seems to work
SELECT * FROM dbo.Test2
SELECT * FROM dbo.TestTables

--Let's try altering the table by dropping a column
ALTER TABLE dbo.Test2 DROP COLUMN SomeOtherName

--Can't do that
Server: Msg 5074, Level 16, State 3, Line 1
The object 'TestTables' is dependent on column 'SomeOtherName'.
Server: Msg 4922, Level 16, State 1, Line 1
ALTER TABLE DROP COLUMN SomeOtherName failed because one or more objects access this column.

--Let's try altering the table by changing a column size
ALTER TABLE dbo.Test2 ALTER COLUMN SomeOtherName VARCHAR(48)

--Same here; this is not allowed
Server: Msg 5074, Level 16, State 3, Line 1
The object 'TestTables' is dependent on column 'SomeOtherName'.
Server: Msg 4922, Level 16, State 1, Line 1
ALTER TABLE ALTER COLUMN SomeOtherName failed because one or more objects access this column.

--Let's drop the column that is not used by the view
ALTER TABLE dbo.Test2 DROP COLUMN Col3

--No problem here either, if a column is not used by the view it can be dropped

--Clean up the mess
DROP VIEW dbo.TestTables
DROP TABLE dbo.Test2, dbo.Test1

So there you have it; SCHEMABINDING is a nice way to protect your views from dropped tables, modified columns or dropped columns on tables that are used in views.

--You can add columns without a problem to the table used by a view.
--You can modify a column that is not used in a view.
--You can also drop a column that is not used in the view

Monday, November 27, 2006

Do You Use Partitioned Views Or Indexed Views In SQL Server 2000

I am in the process of interviewing people for a position at work. The people I have interviewed so far have between 8 and 10 years SQL experience. I noticed one thing; none of these people knew what partition views or horizontal partitioning is or what is involved with creating an index view (the SET options, SCHEMABINDING etc etc). I must say that I was surprised that people who worked with SQL Server since 1998 didn’t know about isolation levels, audit trails, difference between a unique constraint and primary key and the list goes on

So here is my question to you: Do you use partitioned views or indexed views?

I must admit that I have created indexed views only twice on a production box. Partitioned views I am using a lot more since the table that we had grew to 180 million rows and you can query it on a combination of columns. Creating partitioned views is not a big deal but it involves some maintenance if you add years or whatever your partitioned column is. Then you have to create does tables and add them to the view. Luckily SQL Server 2005 has partitioned functions and this makes it a lot easier

So is this an unreasonable question? It’s not like I asked the difference between a conversion and a cycle deadlock is it?

Saturday, November 25, 2006

SQL Server - Best Practices Site Available On TechNet

Microsoft TechNet has a page named SQL Server - Best Practices; this site has white papers, scrips a toolbox and top 10 lists
From the site:

Get the real-world guidelines, expert tips, and rock-solid guidance to take your SQL Server implementation to the next level. Drawing on the extensive experience and expertise from respected developers and engineers at Microsoft as they walk you through the specifics on solving particularly difficult issues.

Here is a preview of some of the material that is available right now:

Technical White Papers
Deep level technical papers on specific SQL Server topics that were tested and validated by SQL Development

• SQL Server 2005 Performance Tuning using Waits and Queues

• TEMPDB Capacity Planning and Concurrency Considerations for Index Create and Rebuild

• Loading Bulk Data into a Partitioned Table

• DBCC SHOWCONTIG Improvements and Comparison between SQL Server 2000 and SQL Server 2005

• Database Mirroring Best Practices and Performance Considerations

Best Practices ToolBox
• Scripts and tools for performance tuning and troubleshooting SQL Server 2005

Top 10 Lists
Summary lists (usually consisting of 10 items) of recommendations, best practices and common issues for specific customer scenarios by the SQL Server Customer Advisory Team.

• Storage Top 10 Best Practices

• OLTP Top 6 Performance Issues for OLTP Applications

Best Practices in SQL Server Books Online• Best Practices for Replication Administration

• Replication Security Best Practices

A must for every SQL Server developer: SQL Server - Best Practices

Friday, November 24, 2006

Auto Update Statistics Asynchronously.

In SQL Server 2000 if the engine determined that the statistics are out of date it would update the statistics and then run the query. If you had a very long table this could take a long time. In SQL server 2005 by turning Auto Update Statistics Asynchronously On the query will run with the old statistics which is not optimal but will probably still be faster than updating the statistics first on a large table and then running the query. The statistics will be updated after the query and the next queries can take advantage of the updated statistics.

Usage:
AUTO_UPDATE_STATISTICS_ASYNC { ON OFF }

ON
Queries that initiate an automatic update of out-of-date statistics will not wait for the statistics to be updated before compiling. Subsequent queries will use the updated statistics when they are available.
OFF
Queries that initiate an automatic update of out-of-date statistics, wait until the updated statistics can be used in the query optimization plan.
Setting this option to ON has no effect unless AUTO_UPDATE_STATISTICS is set to ON.

So how do you enable this? Here is an example for the AdventureWorks database however setting this option to ON has no effect unless AUTO_UPDATE_STATISTICS is also set to ON.

ALTER DATABASE AdventureWorks SET AUTO_UPDATE_STATISTICS_ASYNC ON WITH NO_WAIT

What does Books On Line have to say about this?

Asynchronous Statistics Updates

A query that initiates an update of out-of-date statistics must wait for those statistics to be updated before compiling and returning a result set. This can cause unpredictable query response times and may cause applications that have aggressive time-outs to fail.

In SQL Server 2005, the database option AUTO_UPDATE_STATISTICS_ASYNC provides asynchronous statistics updating. When this option is set to ON, queries do not wait for the statistics to be updated before compiling. Instead, the out-of-date statistics are put on a queue for updating by a worker thread in a background process. The query and any other concurrent queries compile immediately by using the existing out-of-date statistics. Because there is no delay for updated statistics, query response times are predictable; however, the out-of-date statistics may cause the query optimizer to choose a less-efficient query plan. Queries that start after the updated statistics are ready will use those statistics. This may cause the recompilation of cached plans that depend on the older statistics version.

The AUTO_UPDATE_STATISTICS_ASYNC option is set at the database level and determines the update method for all statistics in the database. It is applicable only to statistics updating and cannot be used to asynchronously create statistics. Setting this option to ON has no effect unless AUTO_UPDATE_STATISTICS is also set to ON. By default, the AUTO_UPDATE_STATISTICS_ASYNC option is OFF

Thursday, November 23, 2006

Happy Thanksgiving

This is not going to be a SQL post (again) So to have at least some SQL I am going to link to a post I did last year: Calculating Thanksgiving By Using SQL in SQL Server

So that’s that. I have some people coming over today and still have to cook all the stuff. The best part about thanksgiving besides the food and seeing the family is that we pick our secret Santa. Up until last year we would exchange with every family member and have a limit of $25. No we do it differently we pick one person from a hat and spend $125. This is much better because you only have to buy a gift for one person and you can get a nicer gift instead of several smaller gifts. So I usually give my list of Amazon links to the person and they can choose what to get me. Yes it’s not really a ‘secret’ Santa. I will post my list on Saturday so that you can see if I have any taste or not

Now another topic: weight gain. Yes the time between Thanksgiving and New Years day is the time when most people start putting on the pounds. A friend of mine has a blogpost named Fat America but I must warn you if you are a heavier person you might get offended with some of the language at the end of the post (the elevator part)

Anyway enjoy the food and drinks and have a good time

Windows Vista Consumer Launch Countdown Gadget

There is a Windows Vista Consumer Launch Countdown Gadget available. There are 3 versions of this gadget (widget for you Mac fans) available:
one for Live.com pages, another for Windows Live Spaces, and a third for installation to the Windows Vista Sidebar.

If you need more info about this gadget then visit this link: http://www.livegadgets.net/#blog

Wednesday, November 22, 2006

Upgrading My Skills To SQL Server 2005

At work we are required to get training at least once a year. So I decided to take the Upgrading Your Database Development Skills To Microsoft SQL server 2005

At the end of this post you will see what I should learn. The things that I am most excited about are: Service Broker and Using SQL Management Objects. The new Transact SQL enhancements I know already; I have covered several of them in this blog.

I doubt that I will use the .NET CLR in SQL Server 2005; but I must say that I was amazed at how easy it is to set it up. Notification services could be something I could use but right now I have build my own.
The Native HTTP Support was really cool; it was strange to see WSDL generated from SQL Server. It is something that can be deployed internally since I know that we will never open up our SQL boxes at work to the outside world.

So today is the last day of the class and we have a break now. I must say going to training beats a book anytime. it just saves you so much time. This was a 3 day course. If I had to do it by myself with a book it would take me at least 2 weeks.

Talking about books I am also in the middle of reading Inside Microsoft (r) SQL Server (tm) 2005: The Storage Engine and Pro SQL Server 2005 Database Design and Optimization and both are excellent books

So here is what was covered in this course:

Module 1: SQL Server 2005 Overview

The information in this module introduces the main new features and enhancements in SQL Server 2005 and describes the new development tools.

Lessons
SQL Server 2005 Components and Architecture
SQL Server Developer Tools
SQL Server 2005 Security Implementation

Lab 1: Exploring SQL Server 2005
Using SQL Server Management Studio
Using Schemas

Module 2: Transact-SQL Enhancements in SQL Server 2005

In this module, students learn about the improvements in Transact-SQL in SQL Server 2005.

Lessons
Data Definition Language Enhancements
Data Manipulation Language Enhancements
Structured Exception Handling

Lab 2: Programming with Transact-SQL
Partitioning a Table
Using Common Table Expressions
Using Relational Operators

Module 3: Using XML in SQL Server 2005

In this module, students learn about the XML-related functionality in the SQL Server 2005 database engine will be described.

Lessons
XML Enhancements in SQL Server 2005
The xml Data Type
Using XQuery

Lab 3: Working with XML
Retrieving XML from Relational Data
Storing XML Natively in the Databases
Using XQuery with xml Methods

Module 4: Using Service Broker

The information in this module introduces Microsoftr SQL ServerT 2005 Service Broker-a message-based platform for building service-oriented database solutions.

Lessons
Service Broker Architecture
Using the Service Broker

Lab 4: Using Service Broker
Creating Service Broker Objects
Implementing the Customer Service
Implementing the E-mail Service

Module 5: Using Native HTTP Support

In this module, students learn how to create HTTP endpoints that make database services available to Web services clients.

Lessons
Native HTTP Support in SQL Server 2005
Configuring Native HTTP Support

Lab 5: Implementing a Web Service with HTTP Endpoints
Create an HTTP Endpoint
Test the HTTP Endpoint
Secure the HTTP Endpoint

Module 6: Using Notification Services

The information in this module introduces Notification Services and how to develop Notification Services applications.

Lessons
Notification Services Architecture
Building Notification Services Solutions

Lab 6: Using Notification Services
Creating a Notification Services Application
Creating a Subscription Management Application
Creating an Event Provider

Module 7: Using the .NET CLR in SQL Server 2005

In this module, students learn how to implement managed code in a SQL Server 2005 database.

Lessons
SQL Server and the .NET CLR
Implementing Managed Code in SQL Server 2005

Lab 7: Implementing Managed Code in the Database
Creating a Managed Stored Procedure
Creating a Managed Function
Creating a Managed User-Defined Type

Module 8: Developing Client Applications

The information in this module introduces database developers to client application development techniques that use the data access classes provided in the .NET Framework.

Lessons
Developing Client Applications with ADO.NET
Data Binding in the .NET Framework 2.0

Lab 8: Developing Client Applications
Creating a Data Bound Windows Application
Creating a Data bound ASP.NET Application

Module 9: Using SQL Management Objects

The information in this module introduces the SQL Management Objects (SMO) Application Programming Interface (API) in Microsoftr SQL ServerT 2005, which provides classes that you can use to manage SQL Server. SQL Server 2005 also introduces Replication Management Objects (RMO) to allow automation of replication.

Lessons
Introduction to SQL Management Objects
Replication Management Objects

Lab 9: Using SQL Management Objects
Using SMO to Retrieve Server Information
Using SMO to Create Database Objects
Using SMO to Modify Database Objects

SQL Hacks

O'Reilly came out with their latest SQL book: SQL Hacks
From their site:
Whether you're running Access, MySQL, SQL Server, Oracle, or PostgreSQL, this book will help you push the limits of traditional SQL to squeeze data effectively from your database. The book offers 100 hacks -- unique tips and tools -- that bring you the knowledge of experts who apply what they know in the real world to help you take full advantage of the expressive power of SQL. You'll find practical techniques to address complex data manipulation problems. Learn how to:

--Wrangle data in the most efficient way possible
--Aggregate and organize your data for meaningful and accurate reporting
--Make the most of subqueries, joins, and unions
--Stay on top of the performance of your queries and the server that runs them
--Avoid common SQL security pitfalls, including the dreaded SQL injection attack

Let SQL Hacks serve as your toolbox for digging up and manipulating data. If you love to tinker and optimize, SQL is the perfect technology and SQL Hacks is the must-have book for you.

Sample Chapter
A sample chapter is available: Hack 4: Date Handling (PDF Format)

Table Of Contents:
Chapter 1. SQL Fundamentals
1. Run SQL from the Command Line
2. Connect to SQL from a Program
3. Perform Conditional INSERTs
4. UPDATE the Database
5. Solve a Crossword Puzzle Using SQL
6. Don't Perform the Same Calculation Over and Over

Chapter 2. Joins, Unions, and Views
7. Modify a Schema Without Breaking Existing Queries
8. Filter Rows and Columns
9. Filter on Indexed Columns
10. Convert Subqueries to JOINs
11. Convert Aggregate Subqueries to JOINs
12. Simplify Complicated Updates
13. Choose the Right Join Style for Your Relationships
14. Generate Combinations

Chapter 3. Text Handling
15. Search for Keywords Without LIKE
16. Search for a String Across Columns
17. Solve Anagrams
18. Sort Your Email

Chapter 4. Date Handling
19. Convert Strings to Dates
20. Uncover Trends in Your Data
21. Report on Any Date Criteria
22. Generate Quarterly Reports
23. Second Tuesday of the Month

Chapter 5. Number Crunching
24. Multiply Across a Result Set
25. Keep a Running Total
26. Include the Rows Your JOIN Forgot
27. Identify Overlapping Ranges
28. Avoid Dividing by Zero
29. Other Ways to COUNT
30. Calculate the Maximum of Two Fields
31. Disaggregate a COUNT
32. Cope with Rounding Errors
33. Get Values and Subtotals in One Shot
34. Calculate the Median
35. Tally Results into a Chart
36. Calculate the Distance Between GPS Locations
37. Reconcile Invoices and Remittances
38. Find Transposition Errors
39. Apply a Progressive Tax
40. Calculate Rank

Chapter 6. Online Applications
41. Copy Web Pages into a Table
42. Present Data Graphically Using SVG
43. Add Navigation Features to Web Applications
44. Tunnel into MySQL from Microsoft Access
45. Process Web Server Logs
46. Store Images in a Database
47. Exploit an SQL Injection Vulnerability
48. Prevent an SQL Injection Attack

Chapter 7. Organizing Data
49. Keep Track of Infrequently Changing Values
50. Combine Tables Containing Different Data
51. Display Rows As Columns
52. Display Columns As Rows
53. Clean Inconsistent Records
54. Denormalize Your Tables
55. Import Someone Else's Data
56. Play Matchmaker
57. Generate Unique Sequential Numbers

Chapter 8. Storing Small Amounts of Data
58. Store Parameters in the Database
59. Define Personalized Parameters
60. Create a List of Personalized Parameters
61. Set Security Based on Rows
62. Issue Queries Without Using a Table
63. Generate Rows Without Tables

Chapter 9. Locking and Performance
64. Determine Your Isolation Level
65. Use Pessimistic Locking
66. Use Optimistic Locking
67. Lock Implicitly Within Transactions
68. Cope with Unexpected Redo
69. Execute Functions in the Database
70. Combine Your Queries
71. Extract Lots of Rows
72. Extract a Subset of the Results
73. Mix File and Database Storage
74. Compare and Synchronize Tables
75. Minimize Bandwidth in One-to-Many Joins
76. Compress to Avoid LOBs

Chapter 10. Reporting
77. Fill in Missing Values in a Pivot Table
78. Break It Down by Range
79. Identify Updates Uniquely
80. Play Six Degrees of Kevin Bacon
81. Build Decision Tables
82. Generate Sequential or Missing Data
83. Find the Top n in Each Group
84. Store Comma-Delimited Lists in a Column
85. Traverse a Simple Tree
86. Set Up Queuing in the Database
87. Generate a Calendar
88. Test Two Values from a Subquery
89. Choose Any Three of Five

Chapter 11. Users and Administration
90. Implement Application-Level Accounts
91. Export and Import Table Definitions
92. Deploy Applications
93. Auto-Create Database Users
94. Create Users and Administrators
95. Issue Automatic Updates
96. Create an Audit Trail

Chapter 12. Wider Access
97. Allow an Anonymous Account
98. Find and Stop Long-Running Queries
99. Don't Run Out of Disk Space
100. Run SQL from a Web Page

And for $19.79 on Amazon this is a great gift

Tuesday, November 21, 2006

SQL Server 2005 - Service Pack 2 - Web Chat Today At 9AM PST

The SQL Server Product Team will have a web chat later today
From their site:

If you have any questions regarding Service Pack 2, please join us in a public web chat tomorrow between 9:00am - 10:00am Pacific Time.
Here are a couple of links where you might have already stumbled on this:
http://www.microsoft.com/technet/community/chats/default.mspx
http://www.microsoft.com/communities/chats/default.mspx

Event: Service Pack 2 Web Chat
Date: Tuesday, November 21, 2006
Time: 9:00am - 10:00am (Pacific)

Thanks,

Paul A. Mestemaker II
Program Manager
Microsoft SQL Server Manageability

Sunday, November 19, 2006

Twisted Sister: Twisted Christmas

At work I overheard two people getting excited about the Twisted Sister Christmas album. What?

How in the world can you get excited about that? So I decided to check it out on Amazon. There are 7 reviews and the average is 4 stars. so if you are stuck in the 80's go check it out here

The CD has 10 songs:

1. Have Yourself A Merry Little Christmas
2. Oh Come All Ye Faithful
3. White Christmas
4. I'll Be Home For Christmas
5. Silver Bells
6. I Saw Mommy Kissing Santa Claus
7. Let It Snow, Let It Snow, Let It Snow
8. Deck The Halls
9. The Christmas Song (Chestnuts Roasting On An Open Fire)
10. Heavy Metal Christmas (The Twelve Days Of Christmas)

The biggest surpise is the song Heavy Metal Christmas" which is the Twisted Sister version of "The Twelve Days of Christmas"

Instead of this:

twelve drummers drumming
eleven pipers piping
ten lords a leaping
nine ladies dancing
eight maids a milking
seven swans a swimming
six geese a laying
five gold rings
four calling birds
three french hens
two turtle doves
and a partridge in a pear tree.

You get this gem:

On my heavy metal Christmas my true love gave to me,
12 Silver crosses
11 Black mascaras
10 Pairs of platforms
9 Tattered t-shirts
8 Pentagrams
7 Leather jackets
6 Cans of hairspray
5 Skull earrings
4 Quarts of Jack
3 Studded belts
2 Pairs of spandex pants
And a tattoo of Ozzy!

Fun stuff

Wednesday, November 15, 2006

Visual Studio Team Edition for Database Professionals RTM has been set for Nov. 30, 2006

Microsoft has made a couple of announcements at PASS today; one of them is that the release to manufacture date for Visual Studio Team Edition for Database Professionals has been set for Nov. 30, 2006. Here is what has been announced:

The availability of the community technology preview (CTP) of SP2 for SQL Server 2005 delivers key updates, including data compression, increased business intelligence functionality, security updates relating to Common Criteria, manageability enhancements, support for Windows Vista™ and optimization for the 2007 Microsoft Office system environment. More details about SP2 are available. The SP2 November CTP can be downloaded immediately.

• The RC of SQL Server 2005 Compact Edition is a new offering for essential relational database functionality in a compact footprint. By sharing a familiar SQL syntax and common ADO.NET programming model with other SQL Server editions, SQL Server Compact Edition allows developers and administrators to apply their existing skills and be immediately productive while building and supporting the next generation of applications. The RC is available via Web download.

• The release to manufacture date for Visual Studio Team Edition for Database Professionals has been set for Nov. 30, 2006. Visual Studio Team Edition for Database Professionals provides a foundation for change management, development, testing and deployment of databases through integrated functionality that enables database developers and administrators to be more productive, reduce risk and drive quality. More information can be found on MSDN.

• Plans to provide process guidance for database professionals are included in the Microsoft Solutions Framework. This process guidance is the first of its kind in the industry and demonstrates Microsoft’s commitment to making the database professional a full-fledged participant in the application life cycle.

Going Mobile with SQLServer Compact Edition Podcast On Channel 9

Channel 9 has a podcast about SQL Server Compact Edition. From the site:
"Do you remember when having a mobile phone was a big deal? I can still recall the time when I bought my first “Car Phone” as we called it. It came with a big box that you put under the seat and worked only in the car. It was pretty cool.

Then later I got a big phone that I carried with me on trains and planes and when I made a call people would stare and comment on how important I must be to have such a device. Today even my 12 year old has a mobile phone and my 8 year old wants one. No doubt about it; mobile devices are becoming more and more important every day and I believe that they will become the most pervasive computing platform over time.

The question I have is, what do architects need to know about designing solutions for this platform? Well on this episode I’m joined by Nick Randolph .Net Compact Framework MVP who has been building solutions and has some thoughts for us. "

Download the mp3 or wma version of the podcast here

Tuesday, November 14, 2006

Use SESSIONPROPERTY To Check If NUMERIC_ROUNDABORT Is On Or Off

You want to create an indexed view; however creating an indexed view is not as straight forward as creating an index on a table. The view must be created with the SCHEMABINDING option.

The following SET options must be set to ON when the CREATE INDEX statement is executed:
ANSI_NULLS
ANSI_PADDING
ANSI_WARNINGS
ARITHABORT
CONCAT_NULL_YIELDS_NULL
QUOTED_IDENTIFIER

The NUMERIC_ROUNDABORT option must be set to OFF.

The view must not reference any other views, only base tables. There are more restrictions, you can look them up by reading Creating an Indexed View in Books On Line.

So how do you find out if NUMERIC_ROUNDABORT is set to ON or OFF? Since we are using SQL server 2005 we can use the sys.dm_exec_sessions view

SELECT *
FROM sys.dm_exec_sessions
WHERE session_id = @@spid

But wait there is no column named numeric_roundabort. Okay then let's use the old SQL server 2000 DBCC USEROPTIONS
After executing DBCC USEROPTIONS this is the output for me

DBCC USEROPTIONS
-----------------------------
textsize 64512
language us_english
dateformat ymd
datefirst 7
lock_timeout -1
quoted_identifier SET
arithabort SET
ansi_null_dflt_on SET
ansi_warnings SET
ansi_padding SET
ansi_nulls SET
concat_null_yields_null SET
isolation level read committed

Still no luck. But there is hope because SQL Server 2005 offers the SESSIONPROPERTY function

Let's do a quick test

SET NUMERIC_ROUNDABORT ON
SELECT SESSIONPROPERTY('numeric_roundabort') --1

SET NUMERIC_ROUNDABORT OFF
SELECT SESSIONPROPERTY('numeric_roundabort') --0

Now let's create our own view with all the set options needed for creating indexed views included

CREATE VIEW UserOptionsExpanded
AS
SELECT session_id,concat_null_yields_null,
quoted_identifier,
ansi_nulls,
ansi_padding,
ansi_warnings,
arithabort,SESSIONPROPERTY('numeric_roundabort') AS numeric_roundabort
FROM sys.dm_exec_sessions

Let's select from the view

SELECT *
FROM UserOptionsExpanded
WHERE session_id = @@spid

And yes all the columns are there

Of course we could have just executed the following and be done ;-)

SET ANSI_NULLS ON
SET ANSI_PADDING ON
SET ANSI_WARNINGS ON
SET ARITHABORT ON
SET CONCAT_NULL_YIELDS_NULL ON
SET QUOTED_IDENTIFIER ON
SET NUMERIC_ROUNDABORT OFF

Let's see what else we can pass into the SESSIONPROPERTY function

ANSI_NULLS
Specifies whether the SQL-92 compliant behavior of equals (=) and not equal to (<>) against null values is applied.
1 = ON
0 = OFF

ANSI_PADDING
Controls the way the column stores values shorter than the defined size of the column, and the way the column stores values that have trailing blanks in character and binary data.
1 = ON
0 = OFF

ANSI_WARNINGS
Specifies whether the SQL-92 standard behavior of raising error messages or warnings for certain conditions, including divide-by-zero and arithmetic overflow, is applied.
1 = ON
0 = OFF

ARITHABORT
Determines whether a query is ended when an overflow or a divide-by-zero error occurs during query execution.
1 = ON
0 = OFF

CONCAT_NULL_YIELDS_ NULL
Controls whether concatenation results are treated as null or empty string values.
1 = ON
0 = OFF

NUMERIC_ROUNDABORT
Specifies whether error messages and warnings are generated when rounding in an expression causes a loss of precision.
1 = ON
0 = OFF

QUOTED_IDENTIFIER
Specifies whether SQL-92 rules about how to use quotation marks to delimit identifiers and literal strings are to be followed.
1 = ON
0 = OFF

[Any other string]
NULL = Input is not valid.

So it looks like SESSIONPROPERTY takes only the SET options required to create an indexed view. Interesting indeed.

Monday, November 13, 2006

sys.sp_estimated_rowsize reduction_for_vardecimal

By now you probably know that Service Pack 2 has added new functionality in the SQL Server 2005 Enterprise Edition to provide an alternate storage format that can be used to minimize the disk space needed to store existing decimal and numeric data types. No application changes area are required to use its benefits.

This new storage format, known as vardecimal storage format, stores decimal and numeric data as variable length columns and can be enabled or disabled at a table level on new or existing tables. If you have declared a decimal or numeric column with high precision but most values do not require it, you can potentially save the disk space needed to store the table. A new stored procedure is provided to estimate the reduction in average row size with the new storage format.

So what is the name of this new stored procedure? The name is sys.sp_estimated_rowsize_reduction_for_vardecimal . The proc returns the following columns: avg_rowlen_fixed_format, avg_rowlen_vardecimal_format and row_count

How do you call this proc?
exec sys.sp_estimated_rowsize_reduction_for_vardecimal 'TableName'

If your table is named OrderDetails you would call it like this
exec sys.sp_estimated_rowsize_reduction_for_vardecimal 'OrderDetails'

Read this post from the SQL Server Storage Engine team for more info

Thursday, November 09, 2006

SQL Server 2005 Service Pack 2 CTP (November 2006) Download Links

The other day I wrote that SQL Server 2005 Service Pack 2 CTP would be available; here are the download links:

SQL Server 2005 Service Pack 2 CTP (November 2006)

SQL Server 2005 Express Edition and Tools Service Pack 2 CTP (November 2006)

SQL Server 2005 Books Online Service Pack 2 CTP (November 2006)

Feature Pack for SQL Server 2005 Service Pack 2 CTP (November 2006)

Additional Sources of SQL Server 2005 Information

Enjoy

Wednesday, November 08, 2006

Windows Vista RTM

Vista has been released to manufacturing!

Windows Vista Blog
http://windowsvistablog.com/blogs/windowsvista/archive/2006/11/08/it-s-time.aspx

Media Alert: Microsoft Announces Conference Call With Jim Allchin
http://www.microsoft.com/presspass/press/2006/nov06/11-08AllchinMA.mspx

Q&A: Microsoft Windows Vista Released to Manufacturing
http://www.microsoft.com/presspass/features/2006/nov06/11-08VistaRTM.mspx

Channel 9 also has a video on their site: Jim Allchin: It's time - Windows Vista RTM

Tuesday, November 07, 2006

SQL Server 2005 Service Pack 2 CTP

Microsoft is releasing the SQL Server 2005 Service Pack 2 Community Technology Preview Tuesday, November 7th.

Here are some of the changes:

Database Engine

Maintenance plans are now supported by the SQL Server Database Services installation. Before SP2, you were required to install SQL Server 2005 Integration Services (SSIS) to run maintenance plans on a server-only installation.
Maintenance plans now support multiserver environments, logging to remote servers, and multiple schedules. For more information, see How to: Create Multiserver Maintenance Plans How to: Create a Maintenance Plan and How to: Add or Modify Maintenance Plan Subplan Schedules.
Added new functionality in the SQL Server 2005 Enterprise Edition to provide an alternate storage format that can be used to minimize the disk space needed to store existing decimal and numeric data types. No application changes area are required to use its benefits. This new storage format, known as vardecimal storage format, stores decimal and numeric data as variable length columns and can be enabled or disabled at a table level on new or existing tables. If you have declared a decimal or numeric column with high precision but most values do not require it, you can potentially save the disk space needed to store the table. A new stored procedure is provided to estimate the reduction in average row size with the new storage format.
Added logon triggers and a common criteria compliance enabled Option for sp_configure to support common criteria in the SQL Server 2005 Enterprise Edition.
The sqllogship application is now supported. This application performs a backup, copy, or restore operation and associated clean-up tasks for a log shipping configuration.
Plan cache improvements that provide improved system performance, better use of the available physical memory for database pages, and the ability to return text XML query plans that contain an XML nesting level greater than or equal to 128 by using the new sys.dm_exec_text_query_plan table-valued function.
SMO for Relational Engine Features
- Table.CheckIdentityValue() correctly generates the schema name for the fully qualified object name.
- Column.AddDefaultConstraint() works against table columns for SQL Server 2000 database instances.

To see all the changes go here

SQL Server 2005 Script Repository

Saturday, November 04, 2006

How Are Dates Stored In SQL Server?

Internally dates are stored as 2 integers. The first integer is the number of dates before or after the base date (1900/01/01). The second integer stores the number of clock ticks after midnight, each tick is 1/300 of a second.

So if we run the following code for the base date (1900/01/01)

DECLARE @d DATETIME
SELECT @d = '1900-01-01 00:00:00.000'

SELECT CONVERT(INT,SUBSTRING(CONVERT(VARBINARY(8),@d),1,4)) AS DateInt,
SUBSTRING(CONVERT(VARBINARY(8),@d),1,4) AS DateBinary
SELECT CONVERT(INT,SUBSTRING(CONVERT(VARBINARY(8),@d),5,4)) AS TimeInt, SUBSTRING(CONVERT(VARBINARY(8),@d),5,4) AS TimeBinary
Go

The results are

DateInt DateBinary
----------- ----------
0 0x00000000

TimeInt TimeBinary
----------- ----------
0 0x00000000

If we use the max date 9999/12/31

DECLARE @d DATETIME
SELECT @d = '9999-12-31 23:59:59.997'

SELECT CONVERT(INT,SUBSTRING(CONVERT(VARBINARY(8),@d),1,4)) AS DateInt,
SUBSTRING(CONVERT(VARBINARY(8),@d),1,4) AS DateBinary
SELECT CONVERT(INT,SUBSTRING(CONVERT(VARBINARY(8),@d),5,4)) AS TimeInt, SUBSTRING(CONVERT(VARBINARY(8),@d),5,4) AS TimeBinary
Go

we get the following result

DateInt DateBinary
----------- ----------
2958463 0x002D247F

TimeInt TimeBinary
----------- ----------
25919999 0x018B81FF

If you take binary values and convert to datetime you get the following results

SELECT CONVERT(DATETIME,0x0000000000000001) --1 Tick 1/300 of a second
------------------------------------------------------
--1900-01-01 00:00:00.003

SELECT CONVERT(DATETIME,0x000000000000012C) -- 1 minute = 300 ticks
------------------------------------------------------
--1900-01-01 00:00:01.000

SELECT CONVERT(INT,0x12C) --= 300
SELECT CONVERT(VARBINARY(3),300) --= 0x00012C

SELECT CONVERT(DATETIME,0x0000000100000000) --add 1 day
------------------------------------------------------
--1900-01-02 00:00:00.000

For smalldatetime the time is stored as the number of minutes after midnight

Now here is some fun stuff

DECLARE @d DATETIME
SELECT @d = .0
SELECT @d
GO
------------------------------------------------------
--1900-01-01 00:00:00.000

DECLARE @d DATETIME
SELECT @d = .1
SELECT @d
GO
------------------------------------------------------
--1900-01-01 02:24:00.000

DECLARE @d DATETIME
SELECT @d = .12
SELECT @d
GO
------------------------------------------------------
--1900-01-01 02:52:48.000

DECLARE @d DATETIME
SELECT @d = '0'
SELECT @d
GO
Server: Msg 241, Level 16, State 1, Line 2
Syntax error converting datetime from character string.

DECLARE @d DATETIME
SELECT @d = 0
SELECT @d
GO
------------------------------------------------------
--1900-01-01 00:00:00.000

So there is no implicit conversion, o is fine 'o' is not

DECLARE @d DATETIME
SELECT @d = 20061030
SELECT @d
GO
Server: Msg 8115, Level 16, State 2, Line 2
Arithmetic overflow error converting expression to data type datetime.

DECLARE @d DATETIME
SELECT @d = '20061030'
SELECT @d
GO
------------------------------------------------------
--2006-10-30 00:00:00.000

Here we have the reverse, the varchar value is fine but the int is not.
This happens because the max integer value that a datetime can take is 36523
If we run the following we are okay

DECLARE @d DATETIME
SELECT @d = 2958463
SELECT @d
GO
------------------------------------------------------
--9999-12-31 00:00:00.000

Friday, November 03, 2006

ISO-11179 Naming Conventions

Straight from the man himself comes this statement posted in the microsoft.public.sqlserver.programming forum: "You need to read ISO-11179 so you use proper data element names. You
actually had "tbl-"on the table names! Sometimes "id" id a
prefix and sometimes it is a postfix."

Of course you know who I am talking about? No? Joe Celko of course. So what is ISO-11179?

The 11179 standard is a multipart standard that includes the following parts:

11179-1
Part 1: Framework, introduces and discusses fundamental ideas of data elements, value domains, data element concepts, conceptual domains, and classification schemes essential to the understanding of this set of standards and provides the context for associating the individual parts of ISO/IEC 11179.

11179-2
Part 2: Classification, provides a conceptual model for managing classification schemes. There are many structures used to organize classification schemes and there are many subject matter areas that classification schemes describe. So, this Part also provides a two-faceted classification for classification schemes themselves.

11179-3
Part 3: Registry Metamodel and Basic Attributes, specifies a conceptual model for a metadata registry. It is limited to a set of basic attributes for data elements, data element concepts, value domains, conceptual domains, classification schemes, and other related classes, called administered items. The basic attributes specified for data elements in ISO/IEC 11179-3:1994 are provided in this revision.

11179-4
Part 4: Formulation of Data Definitions, provides guidance on how to develop unambiguous data definitions. A number of specific rules and guidelines are presented in ISO/IEC 11179-4 that specify exactly how a data definition should be formed. A precise, well-formed definition is one of the most critical requirements for shared understanding of an administered item; well-formed definitions are imperative for the exchange of information. Only if every user has a common and exact understanding of the data item can it be exchanged trouble-free.

11179-5
Part 5: Naming and Identification Principles, provides guidance for the identification of administered items. Identification is a broad term for designating, or identifying, a particular data item. Identification can be accomplished in various ways, depending upon the use of the identifier. Identification includes the assignment of numerical identifiers that have no inherent meanings to humans; icons (graphic symbols to which meaning has been assigned); and names with embedded meaning, usually for human understanding, that are associated with the data item's definition and value domain.

11179-6
Part 6: Registration, provides instruction on how a registration applicant may register a data item with a central Registration Authority and the allocation of unique identifiers for each data item. Maintenance of administered items already registered is also specified in this document.

The one that deals with naming conventions is 11179-5 The link will point to a zip file which has a pdf file in it. The TOC of this pdf file is below

Contents
Foreword
1 Scope
2 Normative references
3 Terms and definitions
4 Data Identifiers within a registry
5 Identification
6 Names
6.1 Names in a registry
6.2 Naming conventions
7 Development of naming conventions
7.1 Introduction
7.2 Scope principle
7.3 Authority principle
7.4 Semantic principle
7.5 Syntactic principle
7.6 Lexical principle
7.7 Uniqueness principle
Annex A (informative) Example naming conventions for names within an MDR registry
Annex B (informative) Example naming conventions for Asian languages

So check it out and hopefully you and your team can adapt a common naming conventions instead of having things named like employee_address, EmployeeAddress, employeeAddress and tblEmployeeAddress.

Thursday, November 02, 2006

SQL Teaser

Try to guess what the output will be of the following SQL Select statement (don't worry, you can't get it right ;-)

First guess then run this

SELECT 123.654, 123d6, 123e4, '123'e4

Surprise!!!!!!

I lifted/stole/borrowed the select statement from Mladen Prajdic's blog