Product Documentation

Database Administrator's Guide

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NONTRAN_FILESYS_FLUSH_OFF

NONTRAN_FILESYS_FLUSH_OFF <YES | NO>

FairCom DB suppresses calls to flush updated file system cache pages to disk for all non-TRNLOG data and index files, except during a call to CTFLUSH(). This is a performance enhancement for non-transaction and PREIMG files.

Note that this default behavior may introduce a vulnerability to possible data loss in the event of a system crash if updates to a FairCom DB data or index file have been written to the file system cache but not yet written to disk. This can be mitigated by installing a battery backup (UPS) on the system so the file-system cache can still be flushed in case of a power failure. Note that this does not introduce any vulnerability involving abnormal termination of the FairCom DB Server process, as it only affects file system caching, not c-tree caching behavior.

YES suppresses the flush calls, and NO enables the flush calls. This option can also be changed at runtime.

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