Re: How to speed up record I/O?

CRPence <CRPbottle-/[email protected]> Mon, 04 Jan 2010 11:03:28 -0800
Newsgroups gmane.comp.lang.as400.mi
Organization midrange.com
Message-ID <[email protected]>
   FWiW the FTP for its read\write activity uses only what is 
available to everyone, except system state [which gains nothing in 
speed for the FTP].  A TRCJOB of the processing will expose what 
functions the FTP utility uses for its I/O.  That the FTP utilizes 
the existing interfaces available to everyone, ensures that there is 
no need to test only the one versus multiple interfaces that would 
effect the same.  Thus there would be no reason to waste the effort 
to try to generate calls to the QDBGET* [or other QDB I/O programs] 
using any interface other than those provided by the HLLs.

Regards, Chuck

Mike Amos wrote:
> 
> 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.
> 
> <<SNIP>>
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