Single file databases...

I unfortunately have undertaken a clumsy task, however, I was asking for it. I am facing the problem of having a number of remote clients running applications that generate files of about ~100-200 MB of tabulated (mostly) data. All these files (about 100-200) must be available for post processing by the end user. I suggested that instead of managing this ourselves and ending up with a some hundred flat binary files, we could use a DB storage. This got misinterpreted and I now have to perform some tests with different DBMS where all the remote files have to be concatenated as *blobs* in a *local file*... that is the DBMS must be able to allocate a local file in a directory for each database and store the binary files in there.... I have seen that Interbase can do that, but MySQL cannot. I plan to test DB2 and Postgres but I cannot find any references if they are capable of doing this. Aditionally, I would like to be able to provide a stream to the clients for writing their results directly. I am not sure which system can do that, whether there are considerable performance issues and if I am missing any alternatives.