Tags: ETL, NoSQL
In less than 2 years DB Best professionals have written and posted over 100 technical articles on database migration and management related topics. These articles have gathered more than 20K views, thousands of likes and dozens of comments from various database management professionals from all over the world. In this post we would like to present a concise and informative review of our most rated articles:
10. SAP HANA – a New Database Management System
In 2007 I worked for a company which provided data warehousing solutions. Our biggest client database was about 2-3 TB which was not so much even five years ago, but because of extremely complicated ETL and complex reports we had a lot of troubles. We spent hundreds of hours monthly on code optimization, but every 30 minutes saved on ETL and processing were compensated with monthly data growth and we had to start over and over. Read more>>
9. Extract-Transform-Load (ETL) Technologies – Part 2
ETL tools have been around for some time, have evolved, matured, and now present us with productive environments for Big Data, Data Warehouse, Business Intelligence, and analytics processing. The ETL data processing cycle itself can be simple or highly complex. Most vendor offerings address the diverse requirements well enough although some do better than others. Read more>>
The hype and disinformation that grudgingly prevails in the data warehouse world today brings me to raise the debate to a rational level. Let’s set aside 3NF and STAR schemas for a moment and the many flavors of analytics along with all their technologies. Let’s temporarily ignore e-commerce, database migrations, business intelligence, and data collection and processing systems. Instead let’s look at three different data storage methodologies. Read more>>
7. The Data Vault – What is it? – Why do we need it?
Database systems and applications are no exception. For Big Data or Small Data, knowing and using the right data modeling and methodology is also critical. Today, business uses the Internet to make money yet harvesting the data in an efficient way often develops into a considerable IT challenge. The ongoing debate behind the many issues involved are not the focus of this blog however, the concepts presented here are. Read more>>
6. Extract-Transform-Load (ETL) Technologies – Part 1
From these blogs one should surmise that deciding upon the best database technology (or DBMS vendor) really depends on schema complexities, how you intend to retrieve your data, and how to get it there in the first place. We’re going to dive into this next, but before we do it is imperative that we briefly examine the differences between OLTP and OLAP database designs. Then let’s leave OLTP details for a future blog as I expect most readers already know plenty about transactional database systems. Instead we’ll focus here on OLAP details and how we process Big Data using ETL technologies for data warehouse applications. Read more>>
5. How to Create Autonomous Transactions in SQL Server
You probably heard about autonomous transactions in Oracle. In a few words, using just one pragma directive in a PL/SQL block you can isolate it from the callers’ context, so it becomes independent transaction. It’s quite useful if you want organize data audit and is pretty widely used in production databases. As you might guess these autonomous transactions do not have direct equivalent in Microsoft SQL Server. The only way to isolate a Transact-SQL block from a transaction context is to open a new connection. There are several options here, so let’s start with SSMA approach. Read more>>
4. How to Emulate Oracle Sequences in SQL Server
When migrating Oracle tables to SQL Server, the problem of sequence conversion is one of the most common. SQL Server 2008 does not have any object even distantly resembling an Oracle sequence, and some tradeoffs are inevitable when you make decisions about the mechanisms to implement its behavior in the target system. In SQL Server 2012 Microsoft introduced sequences, but several incompatibilities with Oracle implementation still exist. Read more>>
3. So You Think You Can Search – Comparing Microsoft SQL Server FTS and Apache Lucene
In 1999, when I was in my first year of university, if I wanted to check my e-mail I had to come into a lab. I used to come into the class, open browser, type address and then go out to grab some coffee. Usually when I came back I was really happy to see that at least half of the page had been loaded.
Today people are not so patient. They used to get response from the web-sites at least in a few seconds and if your application is not that fast, you have a problem. In fact, “few seconds” is a very optimistic term. Nowadays we measure response time with milliseconds. Read more>>
2. Column Oriented Database Technologies
Tables of data where rows of fields (also called columns) represent the structural storage and the corresponding SQL queries that select, insert, update, and delete that data. Most database vendors like Oracle, Microsoft, Sybase, Informix, and many others all base their technology on this ANSI standard. Column-oriented databases are indeed what you might surmise; tables of data where columns of data values represent the structural storage. What you might not expect is that on the surface many column-oriented databases look and feel like row oriented databases also using SQL queries in much the same way. Read more>>
1. How to Raise an Exception in SQL Server User Defined Functions
There are a lot of differences between Oracle and MS SQL Server and you will face many of them trying to move your database from one platform to another. If you use SSMA, which is a good thing to do, you can avoid huge amount of manual work, but you will have to solve some specific problems by yourself after SSMA job will be done. One of them can be raising errors from UDF, which you can easily do in Oracle and can’t in SQL Server without some workarounds because of T-SQL limitations for UDF. Read more>>
