How to speed up record I/O?

Hi,

My name is Mike Amos and, several years ago, I was reasonably proficient at MI programming. The past several years, with C/400 and then ILE-C, I have had no need to use anything other than the provided APIs and MI calls supported directly via ILE-C. Today, however, I need to speed up read/write - esp. reads - for record IO. I know that the IBM FTP program does reads much faster than the provided record IO interfaces because FTP reads and sends my 300MB test file twice as fast as I can read it. I have tried every reasonable combination of _Rreadx, read() and fread() that I can think of using both native and IFS interfaces and compiler options.

I have a few questions:

1. Has anyone found that MI calls to the IO functions, QSYS/QGETDBx, etc. can be safely done using in user state at security level 50?

2. Does anyone have any experience regarding faster record IO methods such as use of RPG, MI or any ideas?

3. Accessing the system table to make the calls is not a problem for me, but I have not been able to find documentation for the IO control block/file control block/other control block definitions needed to set up the IO.

Mike Amos (MrA)

P.S. I have also posted appropriate questions regarding this same topic in other news groups including the midrange C400-L group. If there are any other groups that I should post to, please let me know as I am new to midrange.com.

P.S.S I was doing my technical posts via the IBM 400 news groups that are now taken down.