Hello All,
Today I thought
to explain most usefully topic in obiee
i.e. CACHE MANAGEMENT.
Here in
below post you will see, what is the use of cache management, how to configure the
cache file..etc.
What is
Cache Management?
Whenever a
saved request or any dashboard is accessed by one user it can be saved as a
file to cache. So if any other user accessing the same saved request,
instead of waiting for the information to be fetched from the database it can
be reproduced from the cache for a performance improvement
OBIEE has
two levels of caching, one level works at the OBIEE server level and caches the
actual data for a query returned from the database in a file, the other level
is at the OBIEE Presentation Server.
OBIEE 11g Cache
Management:
You can
enable cache in EM.
Go to EM
-> Business Intelligence Folder -> Coreapplication -> Capacity
Management -> Performance (See Below Screen Shots). Bydefault cache is
enable in 11g. You can disable or enable by click on Active changes.
Once you
enable cache it will automatically reflect into “NQSConfig” (See below Screen
Shots).
Path
NQSConfig file:
D:\obieerakeshpatil\instances\instance1\config\OracleBIServerComponent\coreapplication_obis1
Explanations
of cache management
ENABLE=YES
The first
setting here ENABLE controls whether caching is enabled on the OBIEE
server or not. If this is set to NO then the OBIEE server will
not cache any queries, if it is set to YES then query caching will
take place.
DATA_STORAGE_PATHS ="C:\OracleBIData\cache" 500 MB
DATA_STORAGE_PATHS is
a comma delimited list of paths and data limits used for storing the cache
files. This can include multiple locations for storage
i.e. C:\OracleBIData\cache" 500 MB,C:\OracleBIData\cache2"
200 MB. Note that although the docs say that the maximum value is
4GB the actual max value is 4294967295.
MAX_ROWS_PER_CACHE_ENTRY
= 100000
MAX_ROWS_PER_CACHE_ENTRY is
the limit for the number of rows in a single query cache entry, this is
designed to stop huge queries consuming all the cache space.
MAX_CACHE_ENTRY_SIZE
= 1 MB
MAX_CACHE_ENTRY_SIZE is
the maximum physical size for a single entry in the query cache. If there
are queries you want to enter the cache which are not being stored consider
increasing this value to capture those results, Oracle suggest not setting this
to more than 10% of the max storage for the query cache
MAX_CACHE_ENTRIES
= 1000
MAX_CACHE_ENTRIES is
the maximum number of cache entries that can be stored in the query cache, when
this limit is reached the entries are replaced using a Least Recently Used
(LRU) algorithm.
POPULATE_AGGREGATE_ROLLUP_HITS = NO
POPULATE_AGGREGATE_ROLLUP_HITS is
whether to populate the cache with a new entry when it has aggregated data from
a previous cache entry to fulfil a request. By default this is NO.
USE_ADVANCED_HIT_DETECTION
= NO
USE_ADVANCED_HIT_DETECTION if
you set this to YES then an advanced two-pass algorithm will be used to search for
cache entries rather than the normal one-pass. This means you may get
more returns from the cache, but the two-pass algorithm will be computationally
more expensive.
In next post i will update the how to manage cache in Administration tool.
- Thanks
- Rakesh Patil
- rakeshpatil002@gmail.com
