> .. <- the worst syntax I've ever seen.
>

I do not know if it is bad or not.
As I have worked with MS SQL, this syntax ".." is for me familiar.
Because I have never worked with Oracle, "@" is for me "curious".

I think so :
1. if there is SQL stad. then follow it (unfortunately isn't for
external datasources, but "." is using as delimiter for
<catalog>.<schema>.<table>)
2. if there is other RDMBS which has similar feature, then adapt it
(unfortunately there are 2 big players Oracle and MSSQL with different
syntax ... as I have sed "." id preffered for me)
3. if there are no other RDBMS then use own
(for example <datasource>:<table> or <datasource>::<table> ;-) )

-Laco.