SQL 2014: Getting started with OLTP, OLAP, SSIS, SSAS and SSRS

As passionate developer, I come in touch with many technologies, but only a few of them has been so tough to crack as SSAS and SSRS. While learning SSIS, I felt i was learning a lot about datawarehousing, and I couldn't really imagine there could be more to it. At the same time I knew there must be more to it, as SSAS and SSRS was a part of the SQL Server suite.

Now I know that SSIS, SSAS and SSRS can be translated to data gathering, data modelling and data visualisation.

And I have written this post to give a swift explenation of SSIS, SSAS and SSRS so it might be easier for you to get started.

My dream database setup 

Starting with a greenfield project, is often difficult. There no experiences and no knowledge, thereby there is paved no road, to go by when developing the system. In my opinion, the 1st mistake which the most make at this point, is to put it all data in same database. This leads to a monolith system, which is hard to maintain and expand. The 2nd mistake is not to divide the database setup in OLTP and OLAP. This lead to analysis with heavy querying in production and passive historic data also stored in production.

OLTP is an acronym for Online Transaction Processing. In other words, it is the database, which is in the line of business. You can also call it, the database with live data. In my dream setup for at system, i would have a bunch micro services, all supported by their own database. Not necessarily relational databases, I would have the database which fitted the job best. The data in these databases, would be on a journey, which ended in a OLAP system. This journey could span from instant to the lifetime of the system.

OLAP is an acronym for Online analytical Processing. OLAP is almost always, analysed for financial reasons, and therefor it should be the last stop for data. It must not return to OLTP, because it would mean, that history could be re-written which is a problem when it comes to finance.

The process of getting data from OLTP to OLAP, would be data gathering, which is the perfect intro for next topic: SSIS.

SQL Server Integration Services (SSIS)

SSIS has become one of my favourite SQL Server tools. With few drag and drops, it is possible to setup data copy or transformation. Compared to scripting(as a developer I usually prefers scripting), it is so much faster to get something up and running, and also easier to structure. Enough praising.

Referring to OLTP about having several different databases, and SSIS being able to read from different source. It is the perfect tool to support this solution.

DQS (Data Quality Service) and MDS (Master Data Service) are often mention together with SSIS. These tool works only with SQL Server, but if you are all-in with SQL Server these tools are quite good. DQS is for correcting data, as they are gathered. MDS is sort of an authority which distribute a data model through out a system to the connected SQL Server database. It makes sure data integrity is kept.

There is other suppliers of ETL tool for SQL Server, but I only use SSIS.

SQL Server Analysis Services (SSAS)

Even thou data is arranged by stars, and it browsable through excel, it can be better. While a star is easy to imagine, it can be more difficult to imagine an cube, and in the beginning even to realize the difference. A cube is like a dimensional system, as we now it from math. Most of us can imagine 1st, 2nd, 3rd dimensional system. Some of us can even imagine a 4th dimensional system, by collapsing 3 dimensions and add a 4th dimension, so it look 2 dimensional again.

Each dim table in a star, would be a dimension in a cube, but they are still not the same. In principle you could take a star, print out all tables, put the papers on a table and then draw lines for each relation from the dimension tables to the fact table. Where a cube is arranged (as mentioned before) an a virtual dimensional system, it is really not printable, but fast for analysing/browsing.

SSAS Helps you building cubes, so that would be data modelling. It will also assist you to do some data mining. I'll will refrain to speak of data mining with SSAS, because I haven't touch that topic yet.

Working with cubes, is a way in SSAS which called dimensional mode. SSAS has two more modes: PowerPivot and Tabular. It is other ways to model data, and which one is best? It depends. 

But with there is no point in having data modelled, if you can't deliver their information in a readable way.

SQL Server Reporting Services (SSRS)

As you might have guessed SSRS is the visualisation part of the SQL Server suite. There not much to say. It easy to design reports with the editor, you can render reports to various formats and make them available from a reporting server or a share point site.

Take advantages of having SSIS, SSAS and SSRS available

SSIS, SSAS and SSRS are available from SQL Server standard, BI and Enterprise. Not using these tools, when having SQL Server licenses which includes them is as failure. Often have I seen, and have properly in past done myself, custom made reports and based on some analysis directly from the production environment. 

Nobody finds it funny to create custom reports and nobody finds it funny to maintain them. So using SSIS, SSAS and SSRS is a win-win, because it would mean full value from licenses, and developers would use less time on reports and more time on funny stuff.

Getting started 

Getting started with SSAS and SSRS, was a bit hard for me, but fortunately I did stumble in the book: Microsoft SQL Server 2014 Business Intelligence Development: Beginner’s Guide by Raza Red. It is real page turner, which is nice, if you reads a lot of books per year.

It is very comprehensive and filled examples, with good explanations, which I like a lot.

SQL Server 2014: SQL Server Data Tools(SSDT) and Visual Studio 2013 Challenges in Training Kit 70-463 and in general

Level: 2 where 1 is noob and 5 is totally awesome
System: SQL Server 2014

Notice: I'm using the SQL Server 2014 Developer edition, so if you are using a different edition, things might be different.

Some History

I'm currently studying for the exam 70-463 Implementing a Data Warehouse with Microsoft SQL Server 2012, and I'm using the 70-463 training kit for the exam. I have decided to use SQL Server 2014 for the practical training(regarding to SSDT, I now know it is the best to use SQL Server 2014). It has just been released and regarding to exam 70-463 there is no change. People who took the exam for SQL Server 2012 is also certified for SQL Server 2014. For more see FAQ here at http://www.microsoft.com/learning/en-us/sql-certification.aspx.

When using the training kit, you sooner or later realize, it has become a bit outdated. Which is quite natural, because it was published 25. Dec. 2012, and lot have happened since. There has been new releases and updates of Visual Studio, and we even have a new version of SQL Server. Which, all in all is nice.

The first sign of you might be challenged when using the training kit with SQL Server 2014, is in the beginning. The exam kit provides a list of features you have to install, and last on this list is SQL Server Data Tools, also known as SSDT. As you might discover, this feature is not shipped with SQL Server 2014, and it is the most important component for SSIS and the exam 70-463.

SSDT is a Visual Studio plugin, for developing SQL Server Integration Service(SSIS) packages. SSDT is a replacement from Business Intelligence Development Studio, also known as BIDS.Among things, SSDT delivers SSIS packages templates to Visual Studio. SSIS 2012 depends on Visual Studio 2010, Like SSIS 2014 does, but SQL Server 2012 installs the Visual Studio 2010 IDE if none is present. SQL Server 2014 has failed to do so, everytime I have tried to install it. If there is no SSDT in the SQL Server 2014 installation, it might make sense. Also it is okay, because I prefers to use Visual Studio 2013, and if you are a developer like me, I guess you prefer the same.

And Now the Tricky Part

I discovered Microsoft had developed SSDT (SSDT-BI which it is called now) for Visual Studio 2012, it the most easy package to find, and I thought it was the latest. I installed it, and was hit hard in chapter 3 of the training kit 70-463. Because I has installed SSDT-BI 2012 for Visual Studio 2012.

The problem was I have created a SSIS package with the SQL Server Import and Export tool, the version which comes with SQL Server 2014. It stores it SSIS Packages in the SSIS Package format version 8, while the SSDT 2012 stores in the SSIS Package format version 6. The SSIS Package format is apparently not forward compatible. 

The pain I experienced, in chapter 3 of the training kit, was I had to create a package with the SQL Server Import and Export tool (version 2014 in my case) and add it to a SSIS Project created with SSDT 2012. The because the version numbers didn't match, result was this:

Fortunately I succeeded to find SSDT-BI 2014 well hidden at 

http://blogs.msdn.com/b/analysisservices/archive/2014/04/02/sql-server-data-tools-business-intelligence-for-visual-studio-2013-ssdt-bi.aspx

It saves SSIS Packages in SSIS Package format version 8, like the rest of the SQL Server 2014 Suite, plus it works with Visual Studio 2013. I'll expect it will work it with the rest of the training kit 70-463, or else I'll provide a solution on this blog. As bonus info, you have to select "Perform a new installation of SQL Server 2014", or you will get some kind of architecture error. Despite the option name, it only installs SSTD-BI 2014.

Enjoy

 

Migrating from HaveBox 1.6.1 to 2.0.0

It's here, the lastest version of HaveBox. HaveBox 2.0.0. A bump in the major vision number means there are some breaking changes, when migrating from a prior version of HaveBox.

The breaking changes was needed, to get HaveBox in the direction I wanted. My goal is still to keep HaveBox simple, it doesn't mean less features in the future, but on the other hand I will not bloat HaveBox with features. HaveBox 2.0.0 now consist of a core with the basic features build in. Auxiliary features like scanners, config injection or xml configuration, will be added via sub-configs. Sub-config is the key word to extend HaveBox from now on. It should now be possible for everybody, to write a sub-config to customize HaveBox.

The Breaking Changes

Scanners

I have removed the scanner concept from config. I deprecated scanners in version 1.6.0, and from now on, scanner has to be defined sub-configs. HaveBox still comes with a scanner called SimpleScanner, but now it is a sub-config which have to be merged in to the config. See more in the documentation: HaveBox Scanners

Config injection

Config injection has to be enabled by merging in the Config Injection sub-config into the config.  See more in the documentation: Config Injection

Spawning Child Containers

The Spawn methods has been removed. Now you have to configure the life-time, of the singletons in the config section and call CreateChildContainer to create a child container. In this way, it is possible to combine the functionality of the spawn methods. See more in the documentation: Custom life-times

The New Features

TryGetInstance

It now possible to try-getting an instance. It is the same try-get functionality known from the rest of the .NET frameworks. If it succeeds the method returns true, and there will be an instance in the out parameter, else it return false, and there will be NULL in the out parameter.

How About Performance?

HaveBox 2.0.0 has also been optimized for performance. The ilasm has been cleaned and reduced, plus I have written a hashtable to replace Dictionary. The new hashtable is almost twice as fast compared to Dictionary(which also is a hashtable, but less optimal written, check the .NET reference sources.).

The concept app, is showing some nice improvement in performance, but I urge you download HaveBox and do your own testing.

That's all for now

HaveBox 2.0.0 can be downloaded from Nuget: http://www.nuget.org/packages/HaveBox/
The project page: https://bitbucket.org/Have/havebox/downloads

And don't forget to checkout HaveBoxJSON and HaveBoxStates.

Enjoy

C#: Speeding up Dictionary

Level: 2 where 1 is noob and 5 is totally awesome
System: C# on .NET

I like micro optimizing, I find it very funny, relaxing and I learn a lot while doing it. When working on HaveBox, I sometimes discover odd things, which can add performance to HaveBox. Most of the work on HaveBox is micro optimization, which is often expensive and not worth the effort in larger system. But some days ago, when I worked on HaveBox, I did stumble onto something regarding the Dictionary class. It is still micro optimization, but it is so simple and cheap, it might be interesting for other than me.

My Discovery was

When trying to get a value from a key in a Dictionary, the Dictionary class is using a comparer class, to compare the given key with the keys in the dictionary. When instantiating a Dictionary class with the default constructor, The Dictionary class is using the EqualityComparer class as default comparer class. The EqualityComparer class is designed to handle general situations, and is used in other contexts than Dictionary, so it have null checks. These null checks can slow down the Dictionary.

The Trick

As you might have guess, the trick is to write you own comparer, which is amazingly simple. It is inheriting the interface IEqualityComparer, implement the 2 method and then inject it into the Dictionary contructor. Like:

1:  using System;  
2:  using System.Collections.Generic;  
3:  using System.Diagnostics;  
4:    
5:  namespace DictionaryPerformance  
6:  {  
7:    public class Program  
8:    {  
9:      public class DIYCompare : IEqualityComparer<string>  
10:      {  
11:        public bool Equals(string x, string y)  
12:        {  
13:          return x == y;  
14:        }  
15:    
16:        public int GetHashCode(string obj)  
17:        {  
18:          return obj.GetHashCode();  
19:        }  
20:      }  
21:    
22:      static void Main(string[] args)  
23:      {  
24:        IDictionary<string, string> strings = new Dictionary<string, string>();  
25:        IDictionary<string, string> stringsWithDIYCompare = new Dictionary<string, string>(new DIYCompare());  
26:    
27:        for(var i = 0; i < 1000; i++)  
28:        {  
29:          strings.Add("Ipsum " + i, "Not important");  
30:          stringsWithDIYCompare.Add("Ipsum " + i, "Not important");  
31:        }  
32:    
33:        var stopwatch = new Stopwatch();  
34:    
35:        Console.WriteLine("@Intel I5-3337");  
36:    
37:        string tempStr = "";  
38:    
39:        stopwatch.Restart();  
40:        for (var i = 0; i < 1000000; i++)  
41:        {  
42:          strings.TryGetValue("Ipsum 999", out tempStr);  
43:        }  
44:        stopwatch.Stop();  
45:    
46:        Console.WriteLine("Fetched 1 of 1000 elements 1.000.000 times with default comparer and TryGet : {0} ms", stopwatch.ElapsedMilliseconds);  
47:    
48:        stopwatch.Restart();  
49:        for (var i = 0; i < 1000000; i++)  
50:        {  
51:          stringsWithDIYCompare.TryGetValue("Ipsum 999", out tempStr);  
52:        }  
53:        stopwatch.Stop();  
54:    
55:        Console.WriteLine("Fetched 1 of 1000 elements 1.000.000 times with DIY comparer and TryGet : {0} ms", stopwatch.ElapsedMilliseconds);  
56:      }  
57:    }  
58:  }  
59:    

The Numbers

 @Intel I5-3337  
 Fetched 1 of 1000 elements 1.000.000 times with default comparer and TryGet : 56  
  ms  
 Fetched 1 of 1000 elements 1.000.000 times with DIY comparer and TryGet : 49 ms  
 Press any key to continue . . .  

That's all.

Introducing HaveBoxStates. The .NET framework for better flows in your code

Level: 3 where 1 is noob and 5 is totally awesome
System: C# on .NET

Does this looks familiar?

You sketch a program, e.g. a games, like this:

And the implementation ended up, looking like this:

Often it is quite easy to draw a flow of a program or a part of it, but expressing it in code turns out to be hard. This is here where HaveBoxStates comes in. The purpose with HaveBoxStates, is to make it easy to express flows in code, just as we draw them,

HaveBoxStates 

HaveBoxStates is a statemachine/flow engine, to express flows in code. It is very flex and lightweight, and very easy to use. People who has worked with state machines before, might find HaveBoxStates a bit unusual, because the state machine/flow is not defined/configured before use. Even thou it doesn't have strictness predefined in a model, it still as strict. Trying to enter an invalid state would blow up the machine, just as if it was predefined in a model.

Best pratices 

The most important thing I can come up with is, you should always constructor dependency inject your logic into the states. HaveBoxStates comes with HaveBox out of the box, but through a ContainerAdaptor, you can use any container.

How to use it

The following examples are taken from the concept app. So if something needs to be elaborated, you can get the full picture there. Questions in comments is also okay :-). Notice the dependency injection in the PlayGame state.

Here is how to use it:

You draw a flow. It could be this flow:

For each state, you creates a class like this(in separated files, of course):

 using GameStateMachineConcept.Dtos;  
 using GameStateMachineConcept.Dtos;  
 using GameStateMachineConcept.GameEngine;  
 using HaveBoxStates;  
   
 public class Init : IState  
 {  
      public void ExecuteState(IStateMachine statemachine)  
      {  
           statemachine.SetNextStateTo<PlayGame>(new PlayerContext{ Points = 0, Lives = 3, });  
      }  
 }  
   
   
 public class PlayGame : IState  
 {  
      private IGameEngine _gameEngine;  
   
      public PlayGame(IGameEngine gameEngine)  
      {  
           _gameEngine = gameEngine;  
      }  
   
      public void ExecuteState(IStateMachine statemachine, PlayerContext playerContext)  
      {  
           var gameContext = new GameContext { PlayerContext = playerContext, GainedPoints = 0, };  
   
           _gameEngine.Play(gameContext);  
   
           statemachine.SetNextStateTo<Scores>(gameContext);  
      }  
 }  
   
   
 public class Scores : IState  
 {  
      public void ExecuteState(IStateMachine statemachine, GameContext GameContext)  
      {  
           GameContext.PlayerContext.Points += GameContext.GainedPoints;  
   
           if (GameContext.PlayerContext.Lives == 0)  
           {  
                statemachine.SetNextStateTo<Stop>();  
           }  
           else  
           {  
                statemachine.SetNextStateTo<PlayGame>(GameContext.PlayerContext);  
           }  
      }  
 }  
   

Each state must implement an ExecuteState of one of the following signatures:

public void ExecuteState(IStateMachine statemachine)

or

public void ExecuteState(IStateMachine statemachine, <any type> <any name>)

<any type> can be any reference type and <any name> can be any name. The second parameter, is for  DTOs and transferring data between the states. HaveBoxStates automatically cast data to right type, before calling the ExecuteState method.  You just have to give the type of the DTO, forget about casting and just use it.

Because the DTO type can be of any type, and we are not using generics. IState do not enforce implementing of the ExecuteStates, so you have to remember it or else you will get a runtime exception.

The Stop state

HaveBoxStates have one builtin state. The Stop state. If the state machine needs stop, go to the Stop state.

Wrapping it up

Setting up and starting a state machine is also quite easy. Register all states with their dependencies in a container and then instantiate a state machine with the container. Notice, do not register states to IState.

 using GameStateMachineConcept.GameEngine;  
 using GameStateMachineConcept.States;  
 using HaveBox;  
 using HaveBoxStates;  
 using HaveBoxStates.ContainerAdaptors;  
 using System;  
 using System.Collections.Generic;  
   
 namespace GameStateMachineConcept  
 {  
   public class Program  
   {  
     static void Main(string[] args)  
     {  
       var container = new Container();  
       container.Configure(config =>  
       {  
         config.For<IGameEngine>().Use<GameEngine.GameEngine>();  
         config.For<Init>().Use<Init>();  
         config.For<PlayGame>().Use<PlayGame>();  
         config.For<Scores>().Use<Scores>();  
       });  
   
       var stateMachine = new StateMachine(new HaveBoxAdaptor(container));  
       stateMachine.StartStateMachinesAtState<Init>();  
     }  
   }  
 }  
   

That is all :-)

C#: Count() or Length?

Level: 4 where 1 is noob and 5 is totally awesome
System: C# on .NET

Intro

When working with some data structures such as Arrays, strings or alike in C#, we often have 2 choices if we want to know the count of elements in the structure. For most I guess the choice might by easy, people are used to use Count() from LINQ or other structures, so Count() it often is. Length might feel like as, it is just something which pops up, when you scroll the intellisense. You see it, you know what it does, but you prefer Count(), because it makes more sense prosa wise in you code.

Are there any arguments for using Length? Yes.

Performance wise, Length is superior to Count(). Under Count() is some evaluation logic, to count the elements of the structure. Under Length is a pure IL mnemonic, meaning there is directly CLR support for Length.

An Example

I have a reduced IL example, to show what happens IL wise when Length/Count() in C# is compiled:

 .method private hidebysig static void Main(string[] args) cil managed  
 {  
      ...  
      ...  
      ...  
   
      // We initialize 3 variables  
  [0] string[] strings,     // The string array  
  [2] int32 length,         // The length variable  
  [3] int32 count,          // The count variable  
             
      ...  
      ...  
      ...  
   
      // Getting array element count by Length  
  IL_0020: ldloc.0          // puts the string array on the stack  
  IL_0021: ldlen            // using the IL mnemonic for to get length for the array. An unsigned int is returned  
  IL_0022: conv.i4          // The Length variable is a signed int so we convert the output from ldlen  
  IL_0023: stloc.2          // Stores the value, in the variable Length  
   
      ...  
      ...  
      ...  
   
      // Getting array element count by Count()  
  IL_005f: ldloc.0          // puts the string array on the stack  
                            // Next, calling Count() and gets a signed int.  
  IL_0060: call    int32 [System.Core]System.Linq.Enumerable::Count<string>(class [mscorlib]System.Collections.Generic.IEnumerable`1<!!0>)  
  IL_0065: stloc.3          // Stores the value, in the variable count  
      ...  
      ...  
      ...  
    
 } // end of method Program::Main  
   

Performance

To show the difference in performance, I will use the following example:

 using System;  
 using System.Diagnostics;  
 using System.Linq;  
   
 namespace ArrayCount  
 {  
   public class Program  
   {  
     static void Main(string[] args)  
     {  
       var strings = new string[1000];  
       var stopwatch = new Stopwatch();  
       var length = 0;  
       var count = 0;  
   
       Console.WriteLine("@Intel I5-3337");  
   
       stopwatch.Start();  
       for (var i = 0; i < 1000000; i++)  
       {  
         length = strings.Length;  
       }  
       stopwatch.Stop();  
   
       Console.WriteLine("Counted {0} elements by using Length : {1} ms", length, stopwatch.ElapsedMilliseconds);  
   
       stopwatch.Restart();  
       for (var i = 0; i < 1000000; i++)  
       {  
         count = strings.Count();  
       }  
       stopwatch.Stop();  
   
       Console.WriteLine("Counted {0} elements by using Count() : {1} ms", count, stopwatch.ElapsedMilliseconds);  
     }  
   }  
 }  
   

When compiling for release and running it without debugger (shift+f5) the output is:

 @Intel I5-3337  
 Counted 1000 elements by using Length : 0 ms <--- Less than millisecond, not no time:-) 
 Counted 1000 elements by using Count() : 66 ms  
 Press any key to continue . . .  

Conclusion

Now you know the difference between Length and Count(). When performance is preferred Length should always be used, but in general it depends on the context. 

Specification by Small Talk

Level: 4 where 1 is noob and 5 is totally awesome
Disclaimer: If you use anything from any of my blog entries, it is on your own responsibility.

Intro

This a term/method I have coined, based on some good experiences I have had. Just to rule out any misunderstandings, this has nothing to do with the programming language SmallTalk. It is hardly new, and I guess most of you do it to some degree. It is not supposed to replace any specification methods. It is a suggestion for a preamble for whatever specification method is used. It is quite simple, because it is just informel communication.

Motivation

We have come far with different specifications techniques, but how the techniques are executed, sometimes troubles me. Most a companies, often have a pipeline with tasks/projects. The tasks or projects is prioritised after importance, decided on some meeting. When a task or project comes to an end, it usually releases some human resources, which has to be allocated for a new task or projects. Usually a meeting or a workshop is arranged for specifying the task or project.

This is the point which troubles me, and here is why. Without any preamble, we are ironically using a waterfall alike model for specifying. It is like, meet up with you thoughts, specify within this period, see you again at next specify sprint. I know, this is very roughly, but it is for emphasising my point. The thing is, at the first meetings, people mindset and understanding, are not aligned. Often the best responses to input, comes when the input has circled in the mind for couple of days, but by then the specification meeting or workshop is done. Another issues is also, do we have the right people at the meeting? And most importantly, is this task or project in reality the most important, or should another project have the priority? We simply don't have the best start.

So what am I suggesting?

As mention before it is quite simple, it is just talking. The concept is about to find values, share thoughts maybe discuss something technical in a relaxed way, and in the end have an aligned mindset for a specification workshop. The process can run from an idea is born, to when there are resources to bring it to live. Regardless of the work pipeline. The point is, it has to be informal. The idea can be discussed on small informal meetings, maybe by mails or at lunch. Nothing must be settled or promised. The most important part is, involved people should have the time to think about it.

The process starts by someone wants something. As an example, lets say a customers gets an idea for a new feature in the system. He takes contacts his contact from the system supplier company, and tells about the idea. The contact person talk with a coworker about it. Maybe they invite the customer to come by to hear more about it. The co-worker mention the idea at lunch, and then finds out that another coworker, knows a lot about the domain of the idea. Thereby the best person for the job is chosen, instead if the available person at the time. The point is to let idea spread like rings in water through out the company/department. 

Another gain. Maybe the idea is has more value than first anticipated. Maybe it has so much value, that the pipeline has to be reorganised. Projects without values, could even be avoided, by this early evaluation. Value is always best discovered sooner than later. 

Maybe involved developers can test or try things, to improve the idea or give it the best solution. When running a time boxed project, developers do not have much time to do so.

It all sounds good, are there any pitfalls?

Oh Yes. The biggest pitfall is to settle on a solution, so the specification workshop is all about that solution. Some specification techniques, like specification by example, is about focusing on problems, instead of the solutions. In my book, it is the way to specify.

Summary

Specification by small talk, is preparing a project for specification workshop. Less introduction and more focus. It is also for an early evaluation, and preparing for developing. It is a interesting concept I'll explore some more.