Although caching data benefits server performance, it is important to be aware of the effect of caching data on the recoverability of updates. The state of a cached file after an abnormal server termination depends on the c-tree options in effect for that file. Below is a summary of the effect of caching on each file type:
WRITETHRU (PREIMG and non-transaction files): To minimize loss of cached data, the WRITETHRU attribute can be applied to a PREIMG or non-transaction file. WRITETHRU causes writes to be written through the server’s cache to the file system (for low-level updates) or flushed to disk (for ISAM updates). See WRITETHRU Files.