Sreddy, LONGs and LONGRAWs are still supported in 8.x, no problem there. But if the database has LOBs in use, then AFAIK there is no way to convert them back to LONGs, so those tables will not be able to be imported down to 7.x. Also, if you have VARCHAR2 columns defined greater than 2000 you will have troubles. But all this can be resolved by DBA with some compromises, so you can't say that exp-imp from 8.x down to 7.x is something that can be done in general or that you need Oracle Support assistance for that. Exporting from higher version and importing to lower version is totaly viable and documented option, you just have to be avare what can not be created/implemented in lover version.