Data and Index Caching Options

The c-tree Server maintains data and index caches in which it stores the most recently used data images and index nodes. The caches provide high-speed memory access to data record images and index nodes, reducing demand for (slower) disk I/O on data and index files. 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 a cache page contains the requested data record image or index node. When necessary, the server writes pages to disk using a least recently used (LRU) scheme. The server also supports background flushing of cache buffers during system idle times.

The size of the data and index caches are determined by server configuration file settings. It is also possible to disable caching of specific data files and to dedicate a portion of the data cache to specific data files.