A blog about SQL Server, Books, Movies and life in general
Thursday, May 31, 2007
Sam Gentile Reviews RubyMicrosoft Essay By Martin Fowler
Read the article here: http://codebetter.com/blogs/sam.gentile/archive/2007/05/31/microsoft-at-the-crossroads.aspx
Here is the most interesting comment
On the alpha geek side, I fear all is lost already. All of my peers onCodeBetter.com and the "Agile .NET" community have already moved ontoCastle/Windsor, NUNit, NAnt, MonoRail, Spring.NET, NHibernate, etcinstead of Microsoft solutions. It’s virtually over already. For twoyears now, I have talked about our Agile team and how we can't useVisual Studio Team System and instead have to use CruiseControl.NET,NUnit, NAnt, etc to work in an Agile fashion. Not only does Microsoftnot understand this, but the majority of Microsoft programmers don't.They have been weaned on being "Morts" and having wizards, storedprocedures, drag & drop forced on them and not required to learn thesolid skills that make up what we think of as a developer
What is your opinion? We are using Subversion and currently testing with CruiseControl, NAnt and NUnit
Cross-posted from SQLBlog! - http://www.sqlblog.com
Wednesday, May 30, 2007
Speed Up Performance And Slash Your Table Size By 90% By Using Bitwise Logic
You have all seen websites where you can pick a bunch of categories by selection a bunch of check boxes. usually what you do is store those in a lookup table and then you create another table where you store all the categories for each customer.
What if I tell you that you can store all that info in 1 row instead of 10 rows if a customer picked 10 categories.
Take a look at this
1 Classic Rock
2 Hard Rock
4 Speed/Trash Metal
You will store a value of 1 + 2 + 4 = 7(you just sum the values)
Now run this to check, the result will be 7 for a match and some other value otherwise
select 7 | 1,
7 | 2,
7 |3,
7 |4,
7 |5,
7 |6,
7 |7,
7 |8,
7 |20
What is this |(pipe symbol)?
From Books on line
The bitwise operator performs a bitwise logical OR between the two expressions, taking each corresponding bit for both expressions. The bits in the result are set to 1 if either or both bits (for the current bit being resolved) in the input expressions have a value of 1; if neither bit in the input expressions is 1, the bit in the result is set to 0.
The bitwise operator requires two expressions, and it can be used on expressions of only the integer data type category.
Here is how you would typically use this, first create this table
CREATE TABLE NumbersTable (Num int)
INSERT NumbersTable VALUES(1)
INSERT NumbersTable VALUES(2)
INSERT NumbersTable VALUES(3)
INSERT NumbersTable VALUES(4)
INSERT NumbersTable VALUES(5)
INSERT NumbersTable VALUES(6)
INSERT NumbersTable VALUES(7)
INSERT NumbersTable VALUES(8)
INSERT NumbersTable VALUES(9)
INSERT NumbersTable VALUES(10)
INSERT NumbersTable VALUES(11)
INSERT NumbersTable VALUES(12)
GO
Now run this
SELECT Num,
CASE 7 |Num WHEN 7 THEN 'Yes' ELSE 'No' END AS COL
FROM NumbersTable
Here is the output
Num COL
---- ---
1 Yes
2 Yes
3 Yes
4 Yes
5 Yes
6 Yes
7 Yes
8 No
9 No
10 No
11 No
12 No
Okay enough theory let's start with some SQL code. First create this table which will hold all the categories
CREATE TABLE MusicChoice (ID INT PRIMARY KEY,
ChoiceDescription VARCHAR(100))
INSERT MusicChoice VALUES(2,'Hard Rock')
INSERT MusicChoice VALUES(3,'Speed/Trash Metal')
INSERT MusicChoice VALUES(4,'Classical')
INSERT MusicChoice VALUES(5,'Rap')
INSERT MusicChoice VALUES(6,'Blues')
INSERT MusicChoice VALUES(7,'Jazz')
INSERT MusicChoice VALUES(8,'Alternative Rock')
INSERT MusicChoice VALUES(9,'Easy Listening')
INSERT MusicChoice VALUES(10,'Progressive Rock')
INSERT MusicChoice VALUES(11,'Punk Rock')
INSERT MusicChoice VALUES(12,'Swing')
INSERT MusicChoice VALUES(13,'Techno')
INSERT MusicChoice VALUES(14,'Pop')
INSERT MusicChoice VALUES(15,'Disco')
INSERT MusicChoice VALUES(16,'Big Band')
INSERT MusicChoice VALUES(17,'Gospel')
INSERT MusicChoice VALUES(18,'Heavy Metal')
INSERT MusicChoice VALUES(19,'House')
INSERT MusicChoice VALUES(20,'Celtic')
Now create the Bitwise table
CREATE TABLE BitwiseMusicChoice (ID INT PRIMARY KEY,
ChoiceDescription VARCHAR(100))
We will use the POWER function to create the correct values
run this
SELECT id,POWER(2,id-1)BitID,ChoiceDescription
FROM MusicChoice
id BitID ChoiceDescription
1 1 Classic Rock
2 2 Hard Rock
3 4 Speed/Trash Metal
4 8 Classical
5 16 Rap
6 32 Blues
7 64 Jazz
8 128 Alternative Rock
9 256 Easy Listening
10 512 Progressive Rock
11 1024 Punk Rock
12 2048 Swing
13 4096 Techno
14 8192 Pop
15 16384 Disco
16 32768 Big Band
17 65536 Gospel
18 131072 Heavy Metal
19 262144 House
20 524288 Celtic
Now insert it into the BitwiseMusicChoice table
INSERT BitwiseMusicChoice
SELECT POWER(2,id-1)BitID,ChoiceDescription
FROM MusicChoice
Now create this customer table
CREATE TABLE Customer (CustomerID int identity, CustomerCode uniqueidentifier not null)
INSERT Customer VALUES('1DAB5C03-BC23-4FB5-AC3D-A46489459FE9')
INSERT Customer VALUES('F7DDCDBC-F646-493A-B872-4E2E82EA8E14')
INSERT Customer VALUES('E8A4C3D2-AEB0-4821-A49D-3BF085354448')
INSERT Customer VALUES('52581088-C427-4D2F-A782-250564D44D8C')
INSERT Customer VALUES('1B2622C4-6C17-4E74-99D6-336197FBBCFF')
Now we will insert a total of 10000 customers
SET NOCOUNT ON
BEGIN TRAN
DECLARE @LoopCounter INT
SET @LoopCounter = 6
WHILE @LoopCounter <= 10000
BEGIN
INSERT Customer VALUES(NEWID())
SET @LoopCounter = @LoopCounter + 1
END
COMMIT WORK
GO
ALTER TABLE Customer ADD CONSTRAINT pk_Customer PRIMARY KEY (CustomerCode)
Create another table to hold the choices
CREATE TABLE CustomerMusicChoice (id INT identity, MusicChoiceID int, CustomerCode uniqueidentifier)
SET NOCOUNT ON
BEGIN TRAN
DECLARE @LoopCounter INT
DECLARE @CustID uniqueidentifier
SET @LoopCounter = 1
WHILE @LoopCounter <= 10000
BEGIN
SELECT @CustID = CustomerCode
FROM Customer
WHERE CustomerID = @LoopCounter
INSERT Customer VALUES(NEWID())
INSERT CustomerMusicChoice(MusicChoiceID,CustomerCode)
SELECT TOP 10 id,@CustID
FROM MusicChoice
ORDER BY NEWID()
SET @LoopCounter = @LoopCounter + 1
END
COMMIT WORK
GO
Now add these indexes
CREATE INDEX ix_CustomerMusicChoice_Cust On CustomerMusicChoice(CustomerCode)
CREATE
INDEX ix_CustomerMusicChoice_ID On CustomerMusicChoice(MusicChoiceID)Create the BitwiseCustomerMusicChoice which will hold the Bitwise values
CREATE TABLE BitwiseCustomerMusicChoice (id INT identity, MusicChoiceID int, CustomerCode uniqueidentifier not null)
INSERT INTO BitwiseCustomerMusicChoice
SELECT SUM(POWER(2,MusicChoiceID-1)) as MusicChoiceID,CustomerCode
FROM CustomerMusicChoice
GROUP BY CustomerCode
ALTER
Now let's test performance. Hit CTRL + K (SQL 2000) or CTRL + M (SQL 2005)
These 2 queries will return something like this
ID ChoiceDescription Picked
8 Alternative Rock No
16 Big Band No
6 Blues No
20 Celtic No
1 Classic Rock No
4 Classical Yes
15 Disco Yes
9 Easy Listening Yes
17 Gospel No
2 Hard Rock No
18 Heavy Metal Yes
19 House Yes
7 Jazz Yes
14 Pop Yes
10 Progressive Rock Yes
11 Punk Rock No
5 Rap No
3 Speed/Trash Metal Yes
12 Swing Yes
13 Techno No
SELECT mc.ID,ChoiceDescription,CASE WHEN CustomerCode IS NULL THEN 'No' ELSE 'Yes' END Picked
FROM CustomerMusicChoice cmc
RIGHT JOIN MusicChoice mc on cmc.MusicChoiceID = mc.id
AND CustomerCode ='1DAB5C03-BC23-4FB5-AC3D-A46489459FE9'
ORDER BY ChoiceDescription
SELECT bmc.ID,ChoiceDescription,
CASE WHEN bmc.ID |MusicChoiceID =MusicChoiceID THEN 'Yes'
ELSE 'No'
END AS Picked
FROM BitwiseCustomerMusicChoice cmc
CROSS JOIN BitwiseMusicChoice bmc
WHERE CustomerCode ='1DAB5C03-BC23-4FB5-AC3D-A46489459FE9'
ORDER BY ChoiceDescription
67.60% against 32.40% not bad right?
Now run this, we will add AND bmc.ID > 0 to both queries. This will change an index scan to an index seek in the bottom query
SELECT mc.ID,ChoiceDescription,CASE WHEN CustomerCode IS NULL THEN 'No' ELSE 'Yes' END Picked
FROM CustomerMusicChoice cmc
RIGHT JOIN MusicChoice mc on cmc.MusicChoiceID = mc.id
AND CustomerCode ='1DAB5C03-BC23-4FB5-AC3D-A46489459FE9'
AND mc.ID > 0
ORDER BY ChoiceDescription
SELECT bmc.ID,ChoiceDescription,
CASE WHEN bmc.ID |MusicChoiceID =MusicChoiceID THEN 'Yes'
ELSE 'No'
END AS Picked
FROM BitwiseCustomerMusicChoice cmc
CROSS JOIN BitwiseMusicChoice bmc
WHERE CustomerCode ='1DAB5C03-BC23-4FB5-AC3D-A46489459FE9'
AND bmc.ID > 0
ORDER BY ChoiceDescription
That improved the performance a little. 82.75% against 17.25%
Now look at the tables, after running dbcc showcontig you can see that the BitwiseCustomerMusicChoice is about 1/10th the size of the CustomerMusicChoice table which is as expected.
dbcc showcontig ('BitwiseCustomerMusicChoice')
---------------------------------------------------------------------------
DBCC SHOWCONTIG scanning 'BitwiseCustomerMusicChoice' table...
Table: 'BitwiseCustomerMusicChoice' (772197801); index ID: 1, database ID: 26
TABLE level scan performed.
- Pages Scanned................................: 41
- Extents Scanned..............................: 6
- Extent Switches..............................: 5
- Avg. Pages per Extent........................: 6.8
- Scan Density [Best Count:Actual Count].......: 100.00% [6:6]
- Logical Scan Fragmentation ..................: 0.00%
- Extent Scan Fragmentation ...................: 0.00%
- Avg. Bytes Free per Page.....................: 48.0
- Avg. Page Density (full).....................: 99.41%
DBCC execution completed. If DBCC printed error messages, contact your system administrator.
dbcc showcontig ('CustomerMusicChoice')
---------------------------------------------------------------------------
DBCC SHOWCONTIG scanning 'CustomerMusicChoice' table...
Table: 'CustomerMusicChoice' (724197630); index ID: 0, database ID: 26
TABLE level scan performed.
- Pages Scanned................................: 428
- Extents Scanned..............................: 55
- Extent Switches..............................: 54
- Avg. Pages per Extent........................: 7.8
- Scan Density [Best Count:Actual Count].......: 98.18% [54:55]
- Extent Scan Fragmentation ...................: 40.00%
- Avg. Bytes Free per Page.....................: 386.5
- Avg. Page Density (full).....................: 95.22%
DBCC execution completed. If DBCC printed error messages, contact your system administrator.
What happens if you want to get the total count of for example Classical?
SELECT COUNT(*)
FROM CustomerMusicChoice cmc
JOIN MusicChoice mc on cmc.MusicChoiceID = mc.id
WHERE mc.ChoiceDescription ='Classical'
SELECT COUNT(*)
FROM BitwiseCustomerMusicChoice cmc
JOIN BitwiseMusicChoice bmc ON bmc.ID |MusicChoiceID =MusicChoiceID
WHERE bmc.ChoiceDescription ='Classical'
Here are execution plans for SQl Server 2000 and 2005
As you can see SQL Server 2005 has a bigger difference than SQL Server 2000
Now let's look at the overal picture, on a busy system you will have the customer queries running many times an hour/day. The report queries will run maybe a couple a times a day. I think this trade off is perfectly acceptable because overall your system will perform better. Another thing to keep in mind is that instead of 10 inserts you only have to do 1, same with updates, all these little things add up to a lot eventualy.
So as you can see using bitwise logic is a great way to accomplish a couple of things
Reduce table size
Speed up backup and recovery because your table is much smaller
Improve performance
Of course you have to do some testing for yourself because it might not be appropriate for your design. If your system is more of an OLAP than OLTP type of system then don't bother implementing this since it won't help you.
Cross-posted from SQLBlog! - http://www.sqlblog.com
Blogging On sqlblog.com
Here is the link to my blog on sqlblog.com:
http://sqlblog.com/blogs/denis_gobo/default.aspx
Tuesday, May 29, 2007
Check Your SQL For SQL Injection Vulnerabilities By Using These 15 Free SQL Injection Scanners
Securiry Hacks has listed 15 of them, that list is here:
SQLIer
SQLbftools
SQL Injection Brute-forcer - SQLibf
SQLBrute
BobCat
SQLMap
Absinthe
SQL Injection Pen-testing Tool
SQID
Blind SQL Injection Perl Tool
SQL Power Injection Injector
FJ-Injector Framwork
SQLNinja
Automagic SQL Injector
NGSS SQL Injector
Read the details and get the download links here: http://www.security-hacks.com/2007/05/18/top-15-free-sql-injection-scanners
If you are using a lot of dynamic SQL then don't forget to read The Curse and Blessings of Dynamic SQL written by Erland Sommarskog, SQL Server MVP.
Sunday, May 27, 2007
Top 10 .NET Framework Technologies to Learn in 2007. What do you think?
SSIS
SSAS
ServiceBroker
Notification Services
Replication
SQL CLR
T-SQL
You don't and you really can't unless you don't have a life and sit in front of a PC 24/7 but even then it is doubtful
What I have noticed is that a lot of .NET developers didn't do Ajax until MS released ASP.NET Ajax, it is like they are oblivious to the fact that there are other frameworks out there like prototype for example. It is kind of sad that the technology that was first developed by Microsoft and made its way into Outlook Web Access took sooooooo long to get into Visual Studio. Same thing with Nant, Subversion etc etc. I mean how many of you are still using SourceSafe? I am not using it because Subversion is so much better and it's also free (not that that matters because we get it with our MSDN subscriptions anyway).
So open your eyes check CodePlex regularly for new things. Do you know there is a NHibernate.Spatial project? No, did you know that MbUnit 2.4 has been released?
Download it here: http://mb-unit.googlecode.com/files/MbUnit-2.4.197.exe
Here is the list (from help.net)
1) WCF (Windows Communication Foundation): While WCF is certainly less "sexy" than say WPF / Silverlight, it is going to represent the backbone of solving business problems with .NET going forward from here. Big organizations are starting to embrace it, and it provides a cohesive framework for solving business problems in a distributed, integrated way. WCF integrates Remoting, WebServices, EnterpriseServices and Transactions, WSE, MSMQ, and much more into a cohesive programming framework. If you intend to make it your business to study just one new .NET technology this year, make it WCF.
2) ADO.NET (and LINQ): ADO.NET is how you talk to a data store, and databases are such a ubiquitous part of what you will do as a developer that you have NO CHOICE but to become extremely competent in this area. The next big thing in how to talk to data is LINQ with language extensions and entity objects that "represent" mappings of data and its relationships. If you don't become at least familiar with all this stuff, somebody else is going to eat your lunch.
3) WPF (Windows Presentation Foundation): Everything you learned about Windows Forms, pages in a browser, and UI elements is going to go out the window, because Microsoft has already declared that WPF is the new way we're gonna do this stuff. Its already built in to Windows Vista, and the XPS (XML Paper Specification) is already built into the printer subsystem. Don't hang on to the old- get with the new just as fast as you can get your little tushy in gear! And besides that, WPF is just so friggin' cool, it will knock your socks off in hi-def streaming video!
4) SQL Server 2005 (and on): I understand this isn't really .NET, but then again it really is. SQL Server 2005 hosts CLR integration of managed code. That's not only revolutionary, it provides a power to the programmer that you cannot get on other platforms. You have to learn everything you can about SQL Server 2005 including Service Broker, because it will help you to be a better programmer and problem - solver.
5) ASP.NET 2.0: Even non "web programmers" need to understand how this works. The feature set has grown and matured, and you are looking at dynamic languages, LINQ, AJAX, and much more being integrated into the ASP.NET Framework (not to forget Silverlight - the sexiest technology of all of them!).
6) Security. Developers are notoriously weak on security ("Who cares about permission sets - I'm just a Code Monkey"). Unfortunately, we do not live in a perfect world and there are evil people out there who jump with glee when they can mess up your day. The more you become an expert about security, the higher your pay will be: expert security consultants make upwards of $300 / hr.
7) TDD (Test Driven Development): Unit, regression and integration testing aren't a luxury - if you want to develop robust systems then you must have a test protocol. And to do testing right, you need to study how to write tests and what tests to write. There are several excellent books on TDD and at least one that specifically focuses on .NET.
8) Networking (System.Net and related): Networking -- TCP, UDP, HTTP, FTP, and on -- are an integral part of what you need to know how to do in order to glue programs together and make them be able to talk with each other and your data. The more you know about this area, the better equipped you'll be to make the right kind of choices when you are tasked with creating business logic through code.
9) Threading: When asked to develop a multi-threaded object or to use a ThreadPool, 95 out of 100 programmers who claim to be professional .NET developers fall flat on their faces! You need to study all the threading primitives, know how they are used, be able to use the .NET or a custom ThreadPool, and manage threads in your applications.
10) Learning. That's right, I classify learning as a technology. People need to become smarter about how to learn, and especially, WHAT to learn. Just as you become a better programmer when you learn to use the Google or other search engines more effectively, you become a better programmer when you can detail for yourself what you need to learn to be better at your craft, and write down a plan for implementing that learning process.
I would like to have all of them in red but it is time to start specializing just like doctors do, you have to become a specialist. I rather have a lung doctor, an eye doctor and an orthopedic surgeon on my team than 3 physicians who know a little about everything but not a lot about one thing.
Thursday, May 24, 2007
Object Databases Suck RDMBS's Rock
Read the article here: http://blog.hibernate.org/cgi-bin/blosxom.cgi/2007/05/23#in-defence
And remember the latest version of Nhibernate DOES support stored procedures! No more wizard generated SQL that is hard to debug because you don't know what it looks like.
Wednesday, May 23, 2007
Book Review: Pro SQL Server 2005 Database Design and Optimization
By Louis Davidson, Kevin Kline, Kurt Windisch
ISBN: 1590595297
672 pp.
Published: May 2006
Before I start with the book review here is a little story that took place in 1995. A former colleague wanted to open a bar in the East Village (New York City). He looked and looked and found this place somewhere on 9th street. He looked around the place and liked what he saw. Then he went to the back and saw about seven wooden beams against the wall. When he asked about them the owner said that is to keep the wall from collapsing. Anyway my friend settled on another place and opened his bar in a former parking garage, the name of the place is Liquids and it is located on east 10 Street between First Avenue and Avenue A.
Now why am I telling you this story? This story happens in the database world all the time, think of the data model as the foundation of your house if your foundation is weak you need kludges (wooden beams) to prevent your structure from collapsing. How many times do you see on newsgroups questions relating to split string because someone stored a comma delimited string in a column instead of having a lookup table? You have to start with the proper design, once you have that everything else becomes so much easier. It is easy to change a proc or some code somewhere. Once you have to redo your design then you have to also go through all the code and make changes and then also pray that you didn’t break anything. So this is what this book is all about; to teach you how to properly design a data model for speed, concurrency, security, interoperability, integrity and much more. There is no need for triggers when you can use check constraints which in turn will perform much better.
I got my copy of the book the day after our twins were born, that is a little more than 10 months ago. I have read the book many times but I did not read it in the order that it is written in. However I do recommend reading at least the first 5 chapters in the correct order, this is especially true if you are new to databases.
So what do I think of the book? I think that this book is excellent, it is written in a way that is not dry, and you will actually laugh a couple of times when reading this book. The book is written in such a way that it goes into as much detail as necessary to explain the concept and also provides links where needed for material that is not in the scope of the book. Most chapters end with a best practices and a summary section which is very useful if you want to find out what the chapter is about without reading the whole chapter first.
The book has 11 Chapter and 2 appendixes which are listed below
Chapter 1 Introduction to Database Concepts
Chapter 2 Data Modeling
Chapter 3 Conceptual Data Modeling
Chapter 4 The Normalization Process
Chapter 5 Implementing the Base Table Structures
Chapter 6 Protecting the Integrity of Your Data
Chapter 7 Securing Access to the Data
Chapter 8 Table Structures and Indexing
Chapter 9 Coding for Concurrency
Chapter 10 Code-Level Architectural Decisions
Chapter 11 Database Interoperability
APPENDIX A Codd’s 12 Rules for an RDBMS
APPENDIX B Datatype Reference
INDEX
The name of the chapter indicates what the chapter is about, I won’t go into detail by reviewing every chapter.
If you are completely new to SQL then this is the book for you because a good design is the foundation of everything. Now there are two ways to find this out the first way is the easy way. You purchase the book, read it and use the code. The second way is more painful. You have a weak database foundation, performance is bad, customers complain, your boss is breathing down your neck and the only shows you watch on TV are the late shows because you have to update statistics and reindex your database between 7PM and 10PM every single day to make it perform somewhat responsive. If you are an advanced/intermediate developer don’t think that this book is not for you. It is! I have learned a bunch of new tricks/tips which I would not have if I did not read the book. Obviously I am not the only one who praises the book; just take a look at the reviews on Amazon
If you want check out the book first here is the link to the sample chapter: http://www.apress.com/book/supplementDownload.html?bID=10005&sID=3490
Here is the link to Louis’ blog where he posts updates about the book http://drsql.spaces.live.com
I did an interview with Louis a while back, you can find that here
The nest 2 reviews will be Itzik’s and then Adam’s book. I think that Itzik’s will be next week and Adam’s the week after that.
Tuesday, May 22, 2007
Inconvenient Truth???
Notice how he doesn't have an inbox anywhere. Is there a 4th monitor in Al Gore's office to check email??? Surely the guy who invented the internet uses email.
Sunday, May 20, 2007
It's Time For Violence: A song about Databases vs CodeMonkey
First song is Time For Violence
A Song about Databases
Lyrics By Roy Osherove
You can download te mp3 here: http://weblogs.asp.net/rosherove/archive/2007/05/19/it-s-time-for-violence-a-song-about-databases.aspx
Here are some of the lyrics
Hello DB My old friend
I need to work with you again
That stored procedure aint lookin' well
Who wrote that trigger should go to jail
and that index, It is slower than a snail
What the hell
The second song is CodeMonkey by Jonathan Coulton
http://www.jonathancoulton.com/2006/04/14/thing-a-week-29-code-monkey/
Code Monkey get up get coffee
Code Monkey go to job
Code Monkey have boring meeting
With boring manager Rob
Rob say Code Monkey very dilligent
But his output stink
His code not “functional” or “elegant”
What do Code Monkey think?
Code Monkey think maybe manager want to write god damned login page himself
Code Monkey not say it out loud
Code Monkey not crazy, just proud
Code Monkey like Fritos
Code Monkey like Tab and Mountain Dew
Code Monkey very simple man
With big warm fuzzy secret heart:
Code Monkey like you
Code Monkey hang around at front desk
Tell you sweater look nice
Code Monkey offer buy you soda
Bring you cup, bring you ice
You say no thank you for the soda cause
Soda make you fat
Anyway you busy with the telephone
No time for chat
Code Monkey have long walk back to cubicle he sit down pretend to work
Code Monkey not thinking so straight
Code Monkey not feeling so great
Code Monkey like Fritos
Code Monkey like Tab and Mountain Dew
Code Monkey very simple man
With big warm fuzzy secret heart:
Code Monkey like you
Code Monkey like you a lot
Code Monkey have every reason
To get out this place
Code Monkey just keep on working
See your soft pretty face
Much rather wake up, eat a coffee cake
Take bath, take nap
This job “fulfilling in creative way”
Such a load of crap
Code Monkey think someday he have everything even pretty girl like you
Code Monkey just waiting for now
Code Monkey say someday, somehow
Code Monkey like Fritos
Code Monkey like Tab and Mountain Dew
Code Monkey very simple man
With big warm fuzzy secret heart:
Code Monkey like you
And here is the Code Monkey video on YouTube
Wednesday, May 16, 2007
Interview with Adam Machanic Author Of Expert SQL Server 2005 Development
The question-and-answer session with Adam that follows was conducted via email.
What is the audience for this book? Is the book geared towards a beginner/intermediate level user or do you have to be an advanced user to really utilize the information in this book?
The book is certainly not for beginners; I make a lot of assumptions about the level of knowledge possessed by the reader. The reader should understand the basics of writing T-SQL, creating indexes, reading query plans, etc. It's difficult to differentiate between intermediate and advanced users, as everyone has their own opinion of what those levels actually mean! I've covered several not-so-common topics, and my hope is that that almost any SQL Server practitioner who has advanced beyond the basics can learn something from the book.
What are the most important things a person can do to master Transact-SQL?
Practice, practice, and more practice! The more complex queries you write, and the greater the variety of problems you solve in T-SQL, the easier it gets. Just like other programming languages, T-SQL programmers use and reuse various patterns as they work on different projects and problems. Gaining skill in T-SQL is really nothing more than a process of learning when and how to properly apply the patterns to any given situation.
Adam, the first time I came across your name was in the Microsoft public SQL Server programming group. Can you explain to us why you participate in newsgroups and forums?
When I first started working with SQL Server and other Microsoft technologies I discovered Microsoft's news server and was shocked to discover the overall quality and high signal-to-noise ratio compared to many other (Usenet) newsgroups I'd previously frequented. Questions I asked were actually answered--by people who knew what they were talking about, no less! After spending quite some time asking my own questions I realized I could answer a few here and there too, and give something back to the community that had helped me so much. Over time I became hooked. What a great way to kill free time (especially while waiting for software to compile or long queries to run)--not only does it feel good to help others solve their problems, but it also helps to strengthen my skills as a developer. As I mentioned in the previous question, the most important key to software development greatness is practice. By answering newsgroup and forum posts, you can get exposure to all sorts of business problems and scenarios that you would otherwise never see. There is no better learning experience that I have found.
Why is it important to think in sets instead of procedurally?
It's often said that thinking in sets takes advantage of the declarative nature of SQL; and while this is certainly true I think it's important to drill down to why that's such a big deal. SQL query performance, generally speaking, comes down to I/O performance. Too many I/Os, or an I/O-bound system, and your query won't return fast enough--simple as that. When we write set-based queries, we allow the query engine to optimize in order to minimize the number of index requests--and, therefore, I/O operations--necessary to satisfy the query. Working procedurally, with loops, means that the opposite happens--the maximum number of index operations will happen on every invocation, and therefore the query will perform in constant time—at the worst possible level.
Why do you feel it is important to properly unit test procedures?
I cover unit testing in some detail in Chapter 2 of the book, including when and why you want to do it. But what it boils down to is that creating a solid unit test infrastructure helps to guarantee that as you change your code over time, you won't break anything--and if you do, you'll find out about it very quickly. Studies have shown that by far the most expensive part of the software development process is maintenance. This is due to the fact that as we change our software, we break other pieces (dependencies)--and oftentimes, those dependency breaks silently cause subtle issues, that aren't noticed until long after the change was actually made. This can make it extremely difficult to track down and fix the root causes of problems. Comprehensive unit testing makes it possible to eliminate a lot of that delay, by alerting the developer right away if something doesn't look good. This, in turn, results in better quality software, happier customers, more business, and as a result, bigger bonus checks. A win-win situation, if you ask me.
Which chapter was the hardest to write and can you explain why?
Chapter 10, "Working with Temporal Data," took me four months to write. It's my favorite chapter in the book, and one of my favorite topics to think about, but it covers a huge variety of scenarios. As I mention in the chapter, temporal data finds its way into every single database, so it's a large and far-reaching topic. Attempting to cover it in a fairly complete manner turned out to be quite a big task!
Why do you write technical books?
Mainly for the groupies. But aside from that obvious perk, I do it simply because I love sharing technology and techniques with others. Writing a book is similar to participating in a newsgroup or technical forum, but on a much deeper level. Whereas I might answer a question on a forum in 400 words, or write a 3,000-word article, in a book I can cover the same topic in 15,000 or more words--really guide the reader through all of the pitfalls and ins and outs of a given area, and do things that would be impossible in another media (except, perhaps, in a long series of blog posts or articles). Plus, let's be honest--it's just a real thrill seeing my name on the cover of a book!
Who are your favorite authors?
For technical titles, my favorites are Steve McConnell ("Code Complete," "Rapid Development"), Joe Celko ("SQL For Smarties" and others), and Andrew Troelsen ("Pro C# and the .NET Platform"). These authors manage to convey heavy technical topics in very readable formats--which is something I aspire to doing in my own writing.
Unfortunately, I haven't been reading much fiction recently. The last really great novel I read was "Cloud Atlas" by David Mitchell. I'm also a longtime fan of science fiction writers such as William Gibson ("Neuromancer") and Neil Stephenson ("Snow Crash," "Cryptonomicon").
I noticed you have a chapter that deals with application concurrency, do you feel that developers don't have a multi-user/multi-app mindset when first developing the data model/procedures?
With the recent trend towards multiprocessor and multicore machines, threading and synchronization have been hot topics. I've read lots of interviews and articles about how many developers don't understand multithreading well enough. Yet as database developers, I feel like we've been there for years--the database is almost always a shared resource, and managing synchronization is no less important there than in the application tier. A lot of the time we tend to think about concurrency merely in the context of isolation levels and the like, but there is a lot more to it than that--an application will often push much of its synchronization logic all the way into the data tier (whether on purpose or not), and how to properly handle things is really more of a business question than a technical one. When writing that chapter, I tried to frame the issues in terms of business requirements, and then show how to use SQL Server to satisfy them. I think that developers are sometimes prone to getting too excited about technology and trying to find a business problem to which they can apply some new technique--the whole "hammer looking for a nail" mentality--rather than the correct route of determining the business problem and then using technology to solve it.
What SQL Server books are on your bookshelf?
I've now gotten rid of most of my SQL Server 2000 books, except for Ken Henderson's Guru's Guide" series and Kalen Delaney's "Inside SQL Server 2000". My bookshelves (note the plural!) are filled with SQL Server 2005 books--for the first year or so after its release I managed to get almost every new book that was released. I eventually slowed down a bit, but it's hard--there is a lot of great material out there! I'm a really big fan of the "Rational Guides" -- short, concise, yet in-depth guides to just one topic, generally very well-written and easy to digest.
Why did you decide to include a chapter on spatial data?
Through nothing more than luck of the draw I ended up on a couple of projects involving heavy spatial queries, and found that it was an area I really enjoyed. I love to solve difficult problems, and since comparatively very few people are doing spatial in SQL Server, I found that there was a lot of room to innovate--so I ended up having a great time with these projects and totally got hooked. I feel that spatial data is an area we're going to see a lot more of in the future. Spatially-enabled devices are becoming more and more prevalent, and of course all of those devices are going to need data. Unfortunately, due to time constraints I was not able to write that chapter, so my friend Hugo Kornelis tackled it. Hugo did an absolutely fantastic job of covering the topic--I think it's a great chapter, and will help readers get right up to speed.
Are you still making your own beer?
I live in a fairly small apartment at the moment and am somewhat cramped for space as well as time, so I haven't brewed a batch beer for the last couple of years. However, I have been experimenting with ciders quite a bit, and have made a variety of batches using all sorts of adjuncts including honey, brown sugar, and malt extract. Cider is very forgiving and needs to sit around for a long time before it's drinkable, so it's easy to make in a small space with limited time. I've also made a few batches of ginger beer, using a recipe that we actually designed in an online SQL Server forum!
(http://www.simple-talk.com/community/forums/thread/1232.aspx )
Table Of Contents
CHAPTER 1 Software Development Methodologies for the Database World
CHAPTER 2 Testing Database Routines
CHAPTER 3 Errors and Exceptions
CHAPTER 4 Privilege and Authorization
CHAPTER 5 Encryption
CHAPTER 6 SQLCLR: Architecture and Design Considerations
CHAPTER 7 Dynamic T-SQL
CHAPTER 8 Designing Systems for Application Concurrency
CHAPTER 9 Working with Spatial Data
CHAPTER 10 Working with Temporal Data
CHAPTER 11 Trees, Hierarchies, and Graphs
INDEX
Sample: Chapter: Ch. 01 - Software Development Methodologies for the Database World
Amazon Link: Expert SQL Server 2005 Development
Tuesday, May 15, 2007
flickrvision
Who needs animated desktops anymore? Be warned it can get very addictive.
Monday, May 14, 2007
Google: A Girl's Best Friend
she created
she invented
she discovered
she debugged
Look at what Google suggests.
Make Your Case Sensitive Searches 1000 Times Faster
Once I modified my WHERE clause the update took a little less than 3 seconds
Let's get started and see what I did
First create this table
CREATE TABLE #CaseSensitiveSearchTemp (Val CHAR(1))
INSERT #CaseSensitiveSearchTemp VALUES('A')
INSERT #CaseSensitiveSearchTemp VALUES('B')
INSERT #CaseSensitiveSearchTemp VALUES('C')
INSERT #CaseSensitiveSearchTemp VALUES('D')
INSERT #CaseSensitiveSearchTemp VALUES('E')
INSERT #CaseSensitiveSearchTemp VALUES('F')
INSERT #CaseSensitiveSearchTemp VALUES('G')
INSERT #CaseSensitiveSearchTemp VALUES('H')
Now we will insert some lowercase characters
INSERT #CaseSensitiveSearchTemp
SELECT LOWER(Val) FROM #CaseSensitiveSearchTemp
Now we will create our real table which will have 65536 rows
CREATE TABLE CaseSensitiveSearch (Val VARCHAR(50))
We will do a couple of cross joins to generate the data for our queries
INSERT CaseSensitiveSearch
SELECT t1.val + t2.val + t3.val + t4.val
FROM #CaseSensitiveSearchTemp t1
CROSS JOIN #CaseSensitiveSearchTemp t2
CROSS JOIN #CaseSensitiveSearchTemp t3
CROSS JOIN #CaseSensitiveSearchTemp t4
This should give you 65536 rows
SELECT * FROM CaseSensitiveSearch
Create an index on the table
CREATE INDEX IX_SearchVal ON CaseSensitiveSearch(Val)
This is how you do a case sensitive search
SELECT * FROM CaseSensitiveSearch
WHERE Val = 'ABCD' COLLATE SQL_Latin1_General_CP1_CS_AS
Now hit CRLK + K (SQL Server 2000) or CRLK + M(SQL Server 2005)
run these 2 queries in one batch by highlighting them both and hitting F5
SELECT * FROM CaseSensitiveSearch
WHERE Val = 'ABCD' COLLATE SQL_Latin1_General_CP1_CS_AS
SELECT * FROM CaseSensitiveSearch
WHERE Val = 'ABCD' COLLATE SQL_Latin1_General_CP1_CS_AS
AND Val LIKE 'ABCD'
Look at the execution plan, I get 98.71% for the first query and 1.29% for the second query. Just by adding the AND condition SQL server is able to do an index seek and run the query many times faster
Now try it with a lowercase a
SELECT * FROM CaseSensitiveSearch
WHERE Val = 'aBCD' COLLATE SQL_Latin1_General_CP1_CS_AS
SELECT * FROM CaseSensitiveSearch
WHERE Val = 'aBCD' COLLATE SQL_Latin1_General_CP1_CS_AS
AND Val LIKE 'aBCD'
You see it all works without a problem, the correct result is returned
Sunday, May 13, 2007
Great Programming Quote
None of use pasted straight into production code from a newsgroup/forum right? <g>
Thursday, May 10, 2007
Why Does OBJECTPROPERTY Have A TableIsFake Property?
What does BOL say? The table is not real. It is materialized internally on demand by SQL Server. So does this mean it is a table valued function?
Well one way to find out.
Run this
USE AdventureWorks;
GO
SELECT name, object_id, type_desc,OBJECT_DEFINITION(object_id) as object_definition
FROM sys.objects
WHERE OBJECTPROPERTY(object_id, N'TableIsFake') = 1
ORDER BY type_desc, name;
GO
And we get back a table valued function in the resultset
name: ufnGetContactInformation
object_id: 439672614
type_desc: SQL_TABLE_VALUED_FUNCTION
object_definition; CREATE FUNCTION .... (I truncated the rest)
Now create another function
CREATE FUNCTION [dbo].[ufnGetSomeTable]()
RETURNS @SomeTable TABLE (
[ContactID] int PRIMARY KEY NOT NULL)
BEGIN
INSERT @SomeTable VALUES(1)
INSERT @SomeTable VALUES(2)
RETURN
END
GO
Run this to make sure it works
SELECT * FROM ufnGetSomeTable()
run the same query again
USE AdventureWorks;
GO
SELECT name, object_id, type_desc,OBJECT_DEFINITION(object_id) as object_definition
FROM sys.objects
WHERE OBJECTPROPERTY(object_id, N'TableIsFake') = 1
ORDER BY type_desc, name;
GO
And yes we get 2 functions back ;-)
Now we will create some temp tables to see if those are fake
CREATE TABLE #testFakeTable1234 (id int)
CREATE TABLE ##testFakeTable1234 (id int)
Now run this and you will see that those are real and not fake
USE tempdb;
GO
SELECT name, object_id, type_desc,OBJECTPROPERTY(object_id, N'TableIsFake') as IsFake
FROM sys.objects
WHERE name LIKE '#testFakeTable1234%'
OR name LIKE '##testFakeTable1234%'
ORDER BY type_desc, name;
GO
DROP TABLE #testFakeTable1234,##testFakeTable1234
Now create this function
USE AdventureWorks;
GO
CREATE FUNCTION dbo.fn_nums(@n AS BIGINT) RETURNS TABLE
AS
RETURN
WITH
L0 AS(SELECT 1 AS c UNION ALL SELECT 1) ,
Nums AS(SELECT ROW_NUMBER() OVER(ORDER BY c) AS n FROM L0)
SELECT n FROM Nums WHERE n <= @n;
Test it out to make sure it works
SELECT * FROM dbo.fn_nums(2)
Run the following 2 queries
USE AdventureWorks;
GO
SELECT name, object_id, type_desc,OBJECTPROPERTY(object_id, N'TableIsFake') IsFake, OBJECTPROPERTY(object_id, N'IsTableFunction') IsTableFunction
FROM sys.objects
WHERE OBJECTPROPERTY(object_id, N'TableIsFake') <> OBJECTPROPERTY(object_id, N'IsTableFunction')
ORDER BY type_desc, name;
USE AdventureWorks;
GO
SELECT name, object_id, type_desc,OBJECTPROPERTY(object_id, N'TableIsFake') IsFake,
OBJECTPROPERTY(object_id, N'IsInlineFunction') IsInlineFunction
FROM sys.objects
WHERE OBJECTPROPERTY(object_id, N'TableIsFake') <> OBJECTPROPERTY(object_id, N'IsInlineFunction')
ORDER BY type_desc, name;
So a SQL_table valued function is a fake table but a SQL inline table valued function is not a fake table????
So there you have it, confused? Good!