Toad World® Forums

Breaking a Model into Pieces



i am 4 days old learning this stuff, so apologies in for ignorance!

this is not really a TDM specific question, but i hope someone wil be kind enough to give me some pointers as i am learning alone (thanks wikipedia :smiley: )

im creating a logical model which i originally though would be about 6/7 entities, but has grown to around 40 and i cant even see them on the screen all together. i am thinking to break the model into subprojects.

here is a screenshot of my work so far. i have not put relatinship lines in yet, as i know them mentally and i am yet to decide it i should chop up the model into chunks

is this a good idea?

do people who work in this field do this kind of thing, is it possible, or does it create problems or break the relational model?

also, when i get to the point where i am creating a physical database, should i be trying make smaller databases and somehow get them to telk to eachother in the application (or maybe even at the database level?

not sure which dbms i will learn, probably SQL due it its ubiquity and the fact one of the main reasons for learning this stuff is to get a job?



Question #1 - Your thinking is spot on. People normally break models down into subject areas or submodels. In TDM we clal those workspaces (although I keep harping on our dev team to embrace the more popular terminology).

Question #2: “Divide and Conquer” is critical technique in everything we do - remember that people tend to only be able to focus on 3-7 items at a time. So whether some PhD thinks it’s good or not according to book theory - in real life we often have to work in an efficient and productive manaer. Breaking problems into smaller and more manageable pieces is our best tool. So it’s OK.

Question #3: That depends. Oracle and SQL Server mean different things when we say database. So it depends not just on your application being developed - but also to some extent what database paltform. There is no best answer here. So do whatever feels right when thinking about both.

Question #4: Database platform to learn/embrace is like a politics or religion question (i.e. subjective). All the major database platforms (Oracle, SQl Server and DB2) are fine products that a person can pin a career on. My experieince is that is you know one of the big three - you get two benfits. First, moving from one enterprise or inductrial strength database to another is pretty easy. And second, moving down to a smaller fish like MySQL or PostgreSQL is even eaier - sicne they don’t implement much of what the big boys do.

If you’re going dwon the road of windows and visual studio - then MS SQL Server is the best answer. Remember, SQl Server 2005 and 2008 offer a free version (as does Oracle and DB2) that make learning their technology easy and cheap :slight_smile:


wow that was an amazingly fast and comprehensive reply.

thanks a lot, i really appreciate the advice! :slight_smile: