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DASD data sets z/OS DFSMS Macro Instructions for Data Sets SC23-6852-02 |
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The SYNCDEV macro allows you to synchronize data from the following
types of DASD data sets when open for update or output:
For DASD data sets, requests for synchronization information or for partial synchronization cause complete synchronization. The keywords ABUFBLK, BUFBLK, and INQ are ignored. Use the SYNCDEV macro if you need to ensure that a specific record is on DASD at a specific time. Data is always synchronized at CLOSE (or STOW for PDSEs opened with DSORG=PO). SYNCDEV guarantees that the data from previously checked output requests has been written to DASD. If you are using BSAM, you still need to issue a CHECK for each WRITE before issuing the SYNCDEV macro. When using SYNCDEV with QSAM, any records left in your current buffer are held if that buffer is only partially filled. Instead of using the SYNCDEV macro, you can specify "Guaranteed Synchronous Write" through storage class to synchronize the data if the PDSE member is open for update or if the data set is a compressed format data set open for output. See z/OS DFSMSdfp Storage Administration for more information. Restriction: Using SYNCDEV or of "Guaranteed Synchronous Write" can severely degrade performance of data transfer. The SYNCDEV macro can be issued in 24- or 31-bit addressing mode. When issued in 31-bit addressing mode, all addresses must be valid 31-bit addresses. The format of the SYNCDEV macro is:
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Copyright IBM Corporation 1990, 2014
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