It really depends on how much data you have in your table. Best method is usually to select the table directly and set a Data Source Filter to limit rows returned. Are you running 64 bit version of Tableau? If not you will not be able to access the *Gbyte of memory. Don't write custom SQL as this prevents Tableau from creating efficient queries.
Have you tried using the sample data sources supplied with Tableau (like Sample Sales)? Have you looked at the Training & Tutorials links?
It's quite a big table, but can do that with a program like sqldeveloper, so I was expecting Tableau would handle it better.
Yep, 64bits, it does use all the memory.
I'm not writing any custom SQL, I posted it as the example of what I wanted to achieve. As I think it's quite simple, but don't manage to get it done with the drag&drop method.
I've seen a few tutorials, but they seem to show more advanced stuff.