Does someone who has worked extensibly SQL-wise with at least two top DB products (such as Oracle, SQL Server, Informix, Sybase, DB2, Teradata) know how different the DB vendor's SQL dialects are from each other. Since I come from an Oracle background, I am especially interested in
- analytical functions
- model clauses
- hierachical queries (
start with .. connect bycomes to mind)
- any other feature that is more than the usual (
select x, y from a, b where...)
Probably, the question boils down to if and to what extent these features are regulated by an ansi standard.
Practically, I'd like to know if there are "rule of thumbs" that would indicate if (and how) I can take an SQL DML-statement that runs on one database and let it run on an other database.