Evan Barke

Evan Barke

Evan Barke

Having worked on highly transactional production systems and advanced corporate business intelligence, Evan is now using this experience make a difference in the eHealth world. He is driven by the love of technology and a desire to solve complex problems creatively.

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Evan Barke

Latest posts by Evan Barke (see all)

SQL Server Commands – Dynamic SQL

July 4, 2014 by
Warning: This article contains examples of SQL injection. The example queries can be harmful to data and are run on the AdventureWorks2012 database DO NOT run equivalents on your production database. Backup your AdventureWorks2012 database if you don’t want to lose data. Please note that the techniques are purely for education purposes and we do not condone the use of them for any other purpose. Read more »

SQL Server cursor performance problems

June 18, 2014 by

Introduction

In a previous article we discussed the how to set up a basic cursor. We explained that a cursor is a row-based operation that takes a given SELECT statement and breaks downs the processing of the data into looping executions. People that do not have the background in Database Administration or who did not enjoy database classes while studying will often find SQL Server cursors handy and fun to write. This is because they break free of the shackles of set-based logic that is the normal when writing most T-SQL scripts. It is for this reason that we so often find SQL Server cursors written into the business logic of an application and it is a real pity because they are real performance hogs. Yes, there are times when cursors are OK to use and they can be tuned slightly by playing with their different types but, as a general rule of thumb, one should try to avoid them at all costs. Read more »

SQL Server cursor tutorial

June 4, 2014 by

Introduction

Most people that work with Microsoft SQL Server will have at least heard talk of cursors and often, even if people know on a basic level what SQL Server cursors do, they are not always certain when to use them and how to write the code behind them. So this article takes a step back and provides an explanation as to what SQL Server cursors can be used for as well as a basic example that you can run for yourself to test. Read more »

SQL Server Business Intelligence – Using recursive CTE and persisted computed columns to create a calendar table

June 2, 2014 by

Introduction

Those of you that have worked extensively with dates in SQL Server (or any other relational database management system (RDBMS)) will know how finicky and complicated it can be to use DATE functions, DATEPART, DATENAME, DATEADD, GETDATE(), CURRENT_TIMESTAMP etc. Personally, I find it very useful to have a calendar table that stocks all of the necessary, pre-calculated fields in one place. Whether you’re doing BI or web, it can be very helpful to have a fixed ID for a date in order to really optimize your data analysis and processing.
Read more »

SQL Server Business Intelligence – Expanding fact tables in an established data warehouse

May 30, 2014 by

Introduction

As in often the case in life, things that sound simple are not always the easiest things to do. In computer science this is even more often the case. In fact, one of the most challenging things about information technology work is often the communication with bosses that know little about technology and require justification for time spent on seemingly simple tasks. However, by the same token, tasks that seem impossible to the untrained eye are often fairly straightforward and quick to implement and can earn you easy respect. Read more »

SQL Server Business Intelligence features – creating reports based on OLAP cubes

May 19, 2014 by

Introduction

In order to build a SQL Server business intelligence solution one needs to:

  1. Design a de-normalized data warehouse
  2. Build and schedule an Extract, Transform and Load (ETL) package that will feed the data warehouse at regular intervals with new data from the OLTP database.
  3. Setup, personalize and process a cube based on the data warehouse.
  4. Add the processing step to the ETL schedule to ensure the whole chain is automated.
Note: These steps are covered in detail in other articles in the series. If you do not yet have an OLAP cube set up and automated and you need more info as to how to do so; please refer back to the relevant step.
Read more »

SQL Server Business Intelligence Features – Creating a Simple OLAP Cube

May 9, 2014 by

Introduction

Multidimensional cubes and transactional databases are two very different things. From experience I have seen even veteran DBAs avoid the subject of cubes completely because it is too much of an unknown area for them. Often cube work is passed on to developers because of their comfort with using Visual Studio. This is a great pity because it is, in reality, not very difficult at all to create an OLAP cube. It is safe to say that most of the work needs to be done in a traditional SQL Server database engine / SSIS environment from creating the data warehouse model to keeping it fed with ETL packages. This article assumes you already have a data warehouse and uses AdventureWorksDW2012 as an example. Following these steps should put you on the road to a decent SQL Server business intelligence solution based on a read-optimized OLAP cube. Read more »

SQL Server Business Intelligence Features – SQL Server Data Tools – Business Intelligence

April 30, 2014 by

Introduction

In our previous article on the introduction to SQL Server business intelligence we covered the general structure of an enterprise business intelligence solution. The tools needed to build these solutions were briefly mentioned. The purpose of this article is to provide you with a deeper understanding into the creation of an ETL (Extract, Transform and Load) dataflow. To do this one needs to use SQL Server Data Tools – Business Intelligence (previously known as BIDS or Business Intelligence Development Studio). In this article we’ll take a look at the basic functionality of SQL Server Data Tools and how to use it to keep your data warehouse up to date. It’s worth noting that there are many different ways to go about building your ETL solution. This article gives sound advice and pointers as to how to approach the problem. Read more »

SQL Server Business Intelligence – Introduction

April 23, 2014 by

What a load of Bl…

You may be wondering what Business Intelligence is. If you’re reading this article you probably have prior experience with Microsoft SQL Server or at least one other relational database management system (RDBMS). If this is the case you’re probably used to managing a lot of valuable data. If you’re a DBA you may be used to maximizing performance by rewriting stored procedures, creating indexes or running profiling traces.
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