The only issue with getting too deep into mysql is that it can get you into bad practices. Postgres is much more like DB2 / Oracle in terms of SQL syntax and functionality (triggers, stored procedures, etc). Just as an example MySQL makes it easy to do "auto_increment" for a table key, it works totally differently in DB2/Oracle/Postgres.
With regards to items like Stored Procs and Triggers, if you're using mysql you'll write a lot of this stuff in your application layer. This will add to your debugging and maintenance hassles.
Don't get me wrong though, MySQL has it's uses for web content type stuff, but once you get into big financial / transactional applications there are better solutions out there.
The only issue with getting too deep into mysql is that it can get you into bad practices. Postgres is much more like DB2 / Oracle in terms of SQL syntax and functionality (triggers, stored procedures, etc). Just as an example MySQL makes it easy to do "auto_increment" for a table key, it works totally differently in DB2/Oracle/Postgres.
With regards to items like Stored Procs and Triggers, if you're using mysql you'll write a lot of this stuff in your application layer. This will add to your debugging and maintenance hassles.
Don't get me wrong though, MySQL has it's uses for web content type stuff, but once you get into big financial / transactional applications there are better solutions out there.