Additional Caching Features Overview of Oracle CEP Cache Configuration

12-8 Oracle Complex Event Processing Developers Guide cache namesecond-cache-idname ... cache caching-system 6. For each cache, optionally add the following elements that take simple data types to configure the cache: ■ max-size : The number of cache elements in memory after which evictionpaging occurs. The maximum cache size is 2 31 -1 entries; default is 64. ■ eviction-policy : The eviction policy to use when max-size is reached. Supported values are: FIFO, LRU, LFU, and NRU; default value is LFU. ■ time-to-live: The maximum amount of time, in milliseconds, that an entry is cached. Default value is infinite. ■ idle-time: Amount of time, in milliseconds, after which cached entries are actively removed from the cache. Default value is infinite. ■ work-manager-name : The work manager to be used for all asynchronous operations. The value of this element corresponds to the name child element of the work-manager element in the servers config.xml configuration file. For more information, see Section F.44, work-manager . For example: caching-system namecaching-system-idname cache namecache-idname max-size100000max-size eviction-policyLRUeviction-policy time-to-live3600time-to-live cache caching-system 7. Optionally add either write-through or write-behind as a child element of cache to specify synchronous or asynchronous writes to the cache store, respectively. By default, writes to the store are synchronous rite-through which means that as soon as an entry is created or updated the write occurs. If you specify the write-behind element, then the cache store is invoked from a separate thread after a create or update of a cache entry. Use the following optional child elements to further configure the asynchronous writes to the store: ■ work-manager-name : The work manager that handles asynchronous writes to the cache store. If a work manager is specified for the cache itself, this value overrides it for store operations only. The value of this element corresponds to the name child element of the work-manager element in the servers config.xml configuration file. For more information, see Section F.44, work-manager . ■ batch-size : The number of updates that are picked up from the store buffer to write back to the backing store. Default value is 1. ■ buffer-size : The size of the internal store buffer that temporarily holds the asynchronous updates that need to be written to the store. Default value is 100.