4   RMS $open, $close, I/O performance, transactions?   The Question is:     Hello Mr. Wizard,       K I am currently writing software that needs to open (sys$open), write to and E  then close a large file at a frequency of potentially once a second.    N I need to access the file using RMS in Block I/O mode for performance reasons.   N If I keep opening and closing the file to update it (which i have to do), I amN  worried that the disk will rapidly clog up with many versions of what will beN  a large file. I don't think I can concurrently purge the file as I expect the  purge rate to be exc  eeded by the creation rate.     WHAT I WOULD LIKE TO KNOW IS: H Can I open/write/close the file in such a way that the same version gets  written to?   	 Thankyou,     Tom      The Answer is :   >   Performance of this application will be poor, and the record>   access mode has little direct relevence to thi eventuality..   =   Block I/O is not necessarily a performance benefit, and may ;   well be overshadowed by the overhead of the $open and the /   $close and the associatged volume oeprations.    <   You can use $create for the purpose of opening an existing;   file, or creating it if the file does not exist.  See the    CIF flag for details.    ;   Again, opening and closing files in this fashion will not <   necessarily have the performance you appear to seek -- you:   will want to keep the file(s) open, and will want to use>   available operations to flush to disk and/or RMS or database2   journal activities and/or utilize RTR or similar   transaction-related tools.      0  Answer written or last revised on  19-MAR-2004 