Two following questions:
(1) Looks like MS SQL server is popular, but that is only limited to Windows, right? I thought lots of financial companies are using Linux/Unix....
All I know is that our CIO hates them and it is my understanding that the guys across the street (Morgan Stanley) hate them, too. My friends at Markit say it is also being phased out there.from my experience, every database is used out there. From Oracle, Sybase, MySql, MS SQL, Postgress and DB2 to more esoteric ones like KDB and column oriented databases (very good to stored and operate time series data).
Sybase is not on the way out, they have a product that they market specifically to the Financial industry (I think it's called Sybase IQ).
I also hate Sybase, Oracle, MS SQL and DB2 too. So we are on the same boat. They all charge an arm and a leg for their product.
I would also throw in that for some interviews it could be helpful to know some of the generic implementation details in the abstract common across all systems for some development interviews. (IE: Indices, stored procs). In a more development-specific interview, a question may come up like, "Why do developers use stored procedures? Why not just run the query as SQL from the system?" Or, "Let's take a look at this question again, but assume this time that we have an index set up on this column. How would you change your query to take advantage of that?" You don't need to be an expert on the specifics of a database, but if you can reason your way through these questions in the abstract, it will look good in an interview.DB2 or SQL Server have some powerful features. I've seen/updated stored-procedures same as source code with several hundred lines. They were primarily used to aggregate tables from different databases with completely different functions (e.g. inventory data, monitoring data, server information, application configuration).
The complexity was not really needed in many cases, but it was just added optimization (e.g. multiple layers of cursors).
In the end, optimization options for each database type can be learned on the job. GoIllini is correct, understanding SQL is sufficient at interview stage (unless you apply for a DBA position)
MySQL, PostgreSQL, Oracle,...... ?