SQL portability gotchas
database, orm, portability, rdbms-agnostic, sql
Solution
Oracle does not seem to have a problem with cursors, they are a huge performance problem in SQL server.
Actually pretty much all performance tuning is database specific (which is why ANSII standard code often performs very poorly compared to the better methods designed into the specifc flavor of SQL that is database specific).
Dates are another thing that seem to be handled very differntly from database to database.
Datatypes are not equivalent either. One thing that tends to get newcomers to SQL Server is that timestamp data type has absolutely nothing to do with dates and times and cannot be converted to a datatime value.
Problem
My company has me working on finishing a back end for Oracle for a Python ORM. I'm amazed at how much differently RDBMSes do things even for the simple stuff. I've learned a lot about the differences between Oracle and other RDBMSes. Just out of sheer curiosity, I'd like to learn more. What are some common "gotchas" in terms of porting SQL from one platform to another? Please, only one gotcha per answer.