I have a Microsoft Access relational database which I am trying to convert into an ontology for Activity Based Intelligence purposes. I am new to ontologies and was wondering how this would be done. Thanks!
Learn about ontologies, then have at it.
http://doc.utwente.nl/50826/1/thesis_Guizzardi.pdf
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I have a Mysql database. I want to perform multidimensional analyse on this database and build web-based dashboard.
I got little confused between using classic OLAP server like mondrian or SSAS or using dc.js =( d3 + crossfilter) which it provide very nice visualizations
can dc.js be considered as olap server and replace it? is there a way to combine both olap server and dc.js ?
the final objective is to build web application for browse the data in multidimensional way.
thanks for you help
dc.js and OLAP are not comparable.
dc.js takes care of the visualisation, but you need to provide the data (as json or csv), so it still needs something to extract/aggregate the data you need to visualise.
What you use to generate that data is specific to your case, a thin layer on the top of a database might be enough, or may be not and it would work better if you have a more complete datawarehouse (OLAP).
In any case, dc is great if you know what dimensions and graphs you want in your dashboard and can code it, but if you want to have something your users can use to build their own dashboard and queries, other solutions (eg metabase) are probably more adapted.
I'm working on a BI project where i'll use pentaho.
My DW will be modelize as a star schema.
I know that for the analysis part we need to go from this star schema (relational DW) and design the cube thks to schema workbench for example. Thks to that, the analysis tool can do the multidimensional request
For the reporting part, does It also need to know about the cube, or can I just do normal request on the star schema relational DW?
Is it a good or bad thing?
thks for your help
Cubes are for OLAP, which is interactive analysis with Pivot Tables
Your reporting tool, assuming it's not OLAP, should just talk directly to the data warehouse.
I am designing a simple C# WCF service using ASP.NET 4.0 and hosted on IIS7, which will be used by .NET and Java web applications and desktop applications to extract data stored in various databases (both local and remote). I am starting to learn how to use VS2010 and WCF after working for a few years on VS2005 and asp.net web services, so am somewhat of a noob to WCF but know a bit about web services and Visual Studio.
Does anyone have opinions on what the best approach would be in terms of project/class/file setup in Visual Studio 2010 to do this, seeing as how I want to maximize code re-use and minimize development time yet still have the ability to connect to the different databases? I have a WCF Service Application project for the service, and have generated a WCF Client to use for testing using svcutil.exe, but now I'm at the point where I need to start writing database access layer code (or "model" code for MVC if that's the design route I need to go down).
Any help appreciated, thanks!
Each of the databases will have their set of nuisances while integration. The first thing you need to start with would be to design your model in more of OO (Object Oriented) fashion than relation DB way. Once such a model is created, you need to implement mapper layer/classes that would map data from a relational form to a OO format. Then for each DB you need to write some data access code. The amount of code you write for data access may well depend upon the tools\technologies you use. You could look into Entity Framework or NHibernate or other such ORMs to decrease the code required to access data. But keep in mind these ORM mappers may require their own set of tweaks to work well with MySQL, Oracle, SQL Server.
I'm trying to familiarize myself a bit more with database programming, and I'm looking at different ways of creating a data access layer for applications. I've tried out a few ways but there is such a jungle of different database technologies that I don't know what to learn. For instance I've tried using datasets with tableadapters. Using that I am able to switch data provider rather easily (by programming against the interfaces such as IDbConnection). This is one thing I would want to achieve. But I also know everyone's talking about LINQ, and I'm trying to get to know that a bit better too. So I have tried using Linq to Sql classes as the data access layer as well, but apparently this is not provider independent (works only for SQL Server).
So then I read about the Entity Framework (which just as Linq to SQL apparently has gotten its share of bashing already...). It's supposed to be provider independent everybody says, but how? I tried out a tutorial to create an entity data model, but the only providers to choose from were SQL Server/Express. Just for learning purposes, I would like to know how to use the entity framework with MS Access/OleDb.
Also, I would appreciate some input on what is the preferred database technology for data access. Is it LINQ still after all the bashing, or should you just use datasets because they are provider independent? Any pointers for what to learn would be great, because it's just too much to learn it all if I'm not going to use it in the end...!
the only providers to choose from were SQL Server/Express
The .NET Framework only includes EF providers for SQL Server and SQL Server Compact. If you need to access another DBMS, you need to install a third-party provider. For instance, there's a free provider for SQLite, with designer support. There are also a few (commercial) providers made by Devart, for various DBMS. As far as I know, there are no EF providers for OleDB or ODBC...
I really like the metaphor from Scott Hanselman: "I'm not a plumber, but I do know what an S-Bend is."
Personally, I think you should have a working knowledge of all the variety of ways to access data.
ADO.Net, EF, Linq2Sql, txt files, xml etc etc etc.
Have a look at the Nerd Dinner and the Music Store samples. See the way they access data (how do they do Unit Tests, Mocking framework, IOC etc)
Regarding data providers, personally I would avoid Access. It is just as easy to get a Sql Express or Mysql installation running and looks better on your resume.
(For what its worth, this question discusses setting up mysql for EF.)
I currently have an asp.net web application which is using seperate assemblies for the data access, the business logic,
entity objects, and the web user interface. The data access was created using Microsoft's Data Access Application Block
compilied as a .NET 2.0 assembly. Stored procedures were used for the actual moving of data in and out of the database
(SQL 2005).
I would like to update this application to a take advantage of the new features of .NET 3.5 such as Linq, data entities,
etc. What would be the best approach to make this happen?
I was doing some research about this topic and I found this article very useful.
http://blogs.msdn.com/dsimmons/archive/2008/05/17/why-use-the-entity-framework.aspx
Obviously, .net 3.5 has lots of new features if you compare to 2.0. one of them as you stated Linq(to SQL and to XML). which enables you to write strongly-typed language integrated queries. as you may know as well as querying your entities by using LINQ, you can query your collections and XML files.
Also you can use ADO.NET entity framework for mapping your database tables to classes. I am not sure about performance aspect. u might need to do some investigation about it.
dont forget to do your regression tests after you have developed new version of your application.
I know it is general information... I hope it helps.
Cheers