In the previous two parts, we’ve presented the live database model for a subscription-based business and a data warehouse (DWH) we could use for reporting. While it’s obvious that they should work together, there was no connection between these two models. Today, we’ll take that next step and write the code to transfer data from the live database into our DWH.The Data ModelsBefore we dive into the code, let’s remind ourselves of the two models we’ll work with. First is the transactional data model we’ll use to store our real-time data. Taking into account that we run a subscription-based business, we’ll need to store customer and subscription details, customers’ orders, and the order statuses.
Can you design an OLAP database model from an OLTP model? In this article, we’ll show you how!This is the second article of our data warehouse (DWH) series. You can find the first one here . The idea behind the series is to start with the OLTP (Online Transaction Processing) database model, present a possible solution for the reporting/OLAP (Online Analytical Processing) data model, and then finally consider the code we’ll use to perform the ETL process.
Welcome to a new series that shows you the practical side of the data warehouse (DWH)! In the first article, we’ll tackle a data model for a subscription business.In previous data warehouse articles ( The Star Schema , The Snowflake Schema , Star Schema vs. Snowflake Schema ) we focused more on the theory. In this series, we’ll show you how you could create a data warehouse for a real-life application, such as a database model. Today, we’ll take a look at the data model behind a subscription-based business. In upcoming articles, we’ll build a DWH and the code that makes the magic work.
Today, reports and analytics are almost as important as core business. Reports can be built out of your live data; often this approach will do the trick for small- and medium-sized companies without lots of data. But when things get bigger – or the amount of data starts increasing dramatically – it’s time to think about separating your operational and reporting systems.Before we tackle basic data modeling, we need some background on the systems involved. We can roughly divide systems in two categories: operational and reporting systems. Operational systems are often called Online Transaction Processing (OLTP). Reporting and analytical systems are referred to as Online Analytical Processing (OLAP). OLTP systems support business processes. They work with “live” operational data, are highly normalized, and react very quickly to user actions. On the other hand, the primary purpose of the OLAP systems is analytics. These systems use summarized data, which is usually placed in a denormalized data warehousing structure like the star schema. (What is denormalization? Simply put, it’s having redundant data records for the sake of better performance.
There’s a lot to keep in mind when you’re designing a database, and very few of us can remember every valuable tip and trick we’ve learned. So, let’s take a look at some online resources that feature database design tips and best practices. As we go, I’ll share my own opinions on the ideas presented, based on my experience in database design.Obviously, this article is not an exhaustive list, but I’ve tried to review and comment on a cross section of sources. Hopefully, you’ll find the information that best suits your needs and goals.
Introduced in SQL 2012, ColumnStore indexes differ greatly from standard row-based indexes. Intended for OLAP systems, these indexes store data in a highly compressed, segmented fashion with the column as the basis (rather than typical row-based indexes). This type of column-based index allows for great performance gains in data warehouses where table scans, rather than seeks, are performed.ColumnStore indexes have evolved significantly over the last few SQL Server versions:
IntroductionAs I mentioned in my article “OLAP for OLTP practitioners” , I am working on a project that needs to create ananalyticaldatabase for on-line analytical processing (OLAP). I have mostly worked with on-line transaction processing (OLTP) with some limited reporting features. OLAP is a new area for me. In OLAP, the main focus of the database itself is simply to store data for analysis; there is limited maintenance of data. In the previous article, I focused on the differences in
I am currently working on a project where we need to create a database that will be primarily used to store data for reporting and forecasting. In the past, I have mostly worked with databases used for typical CRUD (create, retrieve, update, and delete) operations of data with some limited reporting features. When performing CRUD operations, normalization is important; while in analytics, a de-normalized structure is generally preferred.Here is a simple example of a normalized order table: