“I have the simplest tastes. I am always satisfied with the best.” Oscar Wilde
If we look at market figures, then “Gartner 2012 Worldwide RDBMS market share” reports 48.3 percent revenue share for Oracle.
Three major factors make the Oracle database a clear leader:
1. Remains #1 in worldwide RDBMS software revenue share
2. Holds a larger revenue share than four closest competitors combined
3. Leads next closest competitor revenue share by 29%
But why is that so? Let us have a look at the latest DB-Engines Ranking where Oracle is not only #1 in the DB-Engines Ranking of Relational DBMS but also in the Complete Ranking.
The DB-Engines Ranking are measured the popularity of a system by using the following parameters:
– Number of mentions of the system on websites, measured as number of results in search engines queries.
– General interest in the system.
– Frequency of technical discussions about the system.
– Number of job offers, in which the system is mentioned.
– Number of profiles in professional networks, in which the system is mentioned.
What is the best relational database? The best answer given in answers.yahoo.com is the following: “Define “best”. Oracle is like a BMW. Expensive but has all the fixings. But not everyone needs a BMW. MySQL is like a VW Beetle (the old model). Its cheap, and gets you where you need to go. But you have to tweak it to suit your needs.” Nice explanation!
Next, let us look at Gartner’s Magic Quadrant for Data Warehouse Database Management Systems from January 31st, 2013:
The reason Oracle is top on the “Ability to Execute” scale is simple. It can be described by me with just one word: Exadata. Of all the vendors in this analysis, Oracle reports the highest incidence of nontraditional analytics customers: sectors such as hospitality, energy trading, life sciences and food distribution show up in its reference base. According to Gartner, many of the vertical markets where Oracle has the greatest success contain traditional implementers or late adopters of data warehousing. Oracle’s customers range in annual revenue from $100 million to over $10 billion.
The Business Technology Forum raised the same question: Which is the best enterprise RDBMS database? The article is very much to the point coming to the conclusion that Oracle have the upper hand.
Mirror, Mirror on the Wall, which is the best RDBMS of all? You do not expect an answer from the Mirror “It depends” because anyone trying to be diplomatic will answer that way. Well, at least they say that Oracle is most scalable, most feature rich, and just a wonderful RDBMS.
More to read:
Why would you use Oracle database?
Why Oracle is the Preferred Database Platform?
Is Microsoft’s SQL Server really cheaper than Oracle?
The last one favors SQL Server over Oracle but a word of caution on the credibility on the Oracle side: the author calls PL/SQL “P-SQL” and refers to Active Data Guard as “Advanced Data Guard”.
It will take DB2, SQL Server, Sybase, PostgreSQL and all other key RDBMS players at least several more releases before they can approach the current self-management and tuning capabilities of Oracle Database 11g. But when that day comes, Oracle will not be still at version 11.2.0.
12c is knocking on the door.
Julian Dontcheff's Database Blog 
How much Oracle pay you?
Can’t take this seriously. Exadata is very backwards c.f. DB2 10.5 or SAP HANA.
for you sql server, db2 databases, the scenery never changes if you are not the leader!
Very thoughtful and well-considered. DB2 might still have some features that Oracle hasn’t stolen yet, but they developed most of them years ago.
SQL server will also come in Linux flavors. It is more simple when compared to oracle. While handling huge volume of data my first choice is always goes to MS SQL server. Oracle performance on huge data volume will never reaches SQL server performance. It will take years to fill such gaps.