You configure cache storage and other parameters in Fusion Middleware Control and in the NQSConfig.INI file, for both the query cache and the global cache.
You also must decide on a strategy for flushing outdated cache entries; see Monitoring and Managing the Cache.
This section contains the following topics:
You can use Fusion Middleware Control to enable or disable query caching.
The query cache is enabled by default.
Before you begin this procedure, ensure that you are familiar with the information in Using Fusion Middleware Control.
For information about corresponding configuration file elements, see Mapping User Interface Labels with Configuration File Elements.
You can use Fusion Middleware Control to set the maximum number of cache entries in the query cache and the maximum size for a single cache entry.
Before you begin this procedure, ensure that you are familiar with the information in Using Fusion Middleware Control.
For information about corresponding configuration file elements, see Mapping User Interface Labels with Configuration File Elements.
You can set additional query cache parameters in the NQSConfig.INI file.
Parameters include:
The DATA_STORAGE_PATHS
parameter specifies one or more directories for query cache storage, and the maximum size for each storage directory. These directories are used to store the cached query results and are accessed when a cache hit occurs. See About Cache Hits for more information about when cache is hit.
The cache storage directories reside on high performance storage devices, ideally devoted solely to cache storage. When the cache storage directories begin to fill up, the entries that are least recently used (LRU) are discarded to make space for new entries.
The MAX_ROWS_PER_CACHE_ENTRY
parameter controls the maximum number of rows for any cache entry. Limiting the number of rows is a useful way to avoid using up the cache space with runaway queries that return large numbers of rows. If the number of rows a query returns is greater than the value specified in the MAX_ROWS_PER_CACHE_ENTRY
parameter, then the query is not cached.
Typically, if a query gets a cache hit from a previously executed query, then the new query is not added to the cache. The POPULATE_AGGREGATE_ROLLUP_HITS
parameter overrides this default when the cache hit occurs by rolling up an aggregate from a previously executed query.
See Configuration File Settings for more information about the additional query cache parameters.
Setting global cache parameters ensures consistency across system cache configurations.
Before you begin this procedure, ensure that you are familiar with the information in Using Fusion Middleware Control.
For information about corresponding configuration file elements, see Mapping User Interface Labels with Configuration File Elements.
You can set additional global cache parameters in the NQSConfig.INI file.
Parameters include:
The MAX_GLOBAL_CACHE_ENTRIES
parameter controls the maximum number of entries that are allowed in the global cache store.
The CACHE_POLL_SECONDS
parameter specifies the interval in seconds at which the Oracle BI Server pulls from the logical event queue to synchronize with other server nodes in the cluster.
The CLUSTER_AWARE_CACHE_LOGGING
parameter controls whether logging is turned on for the global cache. Change this setting to YES
only for debugging purposes.
Log entries appear in nqquery.log. You can find this file at:
BI_DOMAIN/servers/obisn/logs