Deferred write processing is a process that writes pages that have been updated in the global buffer onto the disk whenever a particular number of pages has been updated (rather than when a COMMIT statement is issued). The point in time at which the number of updated pages has reached the particular value (which is determined by HiRDB) is called the deferred write trigger.

The number of updated pages to be written onto the disk is determined by HiRDB on the basis on the updated output page rate at the deferred write trigger that is specified in the -w option of the pdbuffer operand. When deferred write processing is in effect, data is not written onto the disk even when a COMMIT statement is issued, thus reducing the input/output processing load.

For details about using deferred write processing, see the HiRDB Version 8 Installation and Design Guide.

Setting up deferred write processing

Deferred write processing is used by specifying both the pd_dbsync_point and the pdbuffer operands of the system common definition. For details about the pd_dbsync_point and pdbuffer operands, see the HiRDB Version 8 System Definition.