ILE C/C++ Programmer's Guide


Blocking Records

You can use record blocking to improve the performance of I/O operations on files that are opened for input or output only. Specify the blksize=value parameter on a call to the fopen() function or the blkrcd=y on a call to the _Ropen() function to turn on record blocking. In some situations, the operating system will return only one record in the block when processing a file. In these cases there is no performance gain.

You can turn off record blocking without changing your program by specifying SEQONLY(*YES) on the OVRDBF command.

Note:
When record blocking is in effect, the I/O feedback structure is updated only when a block of records is transferred between your program and the system.


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