The c-treeACE Server maintains data and index caches in which it stores the most recently used data images and index nodes. These caches provide high-speed memory access to this information, reducing demand for slower disk I/O. The server writes data and index updates first to cache and eventually to disk. Data and index reads are satisfied from the server’s cache if possible. When necessary, the server writes parts of the cache to disk using a least recently used (LRU) scheme. The server also supports background flushing of cache buffers during system idle times.
The cache sizes are determined by the server configuration file. It is possible to disable caching of specific data files and to dedicate a portion of the data cache to specified data files.