This document discusses cache management in Oracle Business Intelligence. It explains how caching works at different levels, including the web browser, presentation server, query results, and physical tables. It also provides details on setting up caching, viewing the cache, clearing the cache, and scheduling cache population and clearing. Tips are provided on bypassing caching and optimizing performance using cached and real-time data sources.

1. Author
:
Project :
Contains :
Rick Brobbel
Oracle BIEE
Cache Management
Date printed :
Page :
Date :
10/12/13
1 of 12
10/12/13
Oracle BI - Cache Management
1
Introduction
1
2
3
4
2
Caching in Oracle BI is an extremely smart and powerful mechanism to drastically increase
performance and response times. This page explains how it works and how you set it up and how
you can influence it.
How it works
5
6
7
On the BI Server (partially in memory, but mostly in files) the results of BI Analytics can be cached.
The purpose is that any user requiring data that has already been requested by another user can
give immediate response, without querying the database or datawarehouse.
8
9
10
11
12
13
Therefore the BI Server will try to (partially) match the logical request to the contents of the cache
files. When a hit is found, the results are returned to the new user. When not the BI Server will
generate the SQL-query and request the information from the database.
The database itself has caching as well and uses statistics for optimization of queries and datasets.
This topic is not discussed here.
2.1
Seeding the cache
14
15
16
17
Any user running a specific analytics for the first time will seed the cache. The logfiles of the BI
Server will show that a cache ID is created and the query and result set is stored in cache files in
the file system of the BI Server.
Reference: Oracle BI - Cache Management-v11-20131210_1236.docx
 Cadran Consultancy b.v.

2. Author
:
Project :
Contains :
2.2
Rick Brobbel
Oracle BIEE
Cache Management
Date printed :
Page :
Date :
10/12/13
2 of 12
10/12/13
Hitting the cache
1
There are a couple of levels involved here:
Level
Comments
Web Browser The user is working in a web browser such as MS Internet Explorer , Google
Cache
Chrome
or Mozilla Firefox . This software runs on a PC or laptop and uses
temporary internet files and cookies to generate and reuse the specific HTML-page
that is on the screen. When the browser is refreshed this 'cache' is used to show a
HTML-page as quick as possible when no changes in the contents exist. This
helps this one user with his or hers individual screens.
BI Presentation The BI Server uses the BI Presentation Server Component to generate the HTMLServer Cache content for that browser. The BI Server will keep track of the Dashboards and
Analytics and Views generated. These objects are cached so they can be reused.
If for instance a user switches between Graph- and a Table-view both views are
cached for reuse. This is stored in cache, so regardless of the underlying data the
BI Presentation Server cache is keeping track of the 'pictures' that have been on
users' screens. This information is not user dependent, so the first user touching
views generates caching for other users to follow as well.
BI Table
The BI Server does the same with the queries, filters and physical tables and
Cache
keeps track of the SQL-statements executed and the result sets returned. This
itself has a couple of components and levels:
Level
Comments
Example
Query The logical request and result set is stored in Show me the revenue
and sold quantities per
Cache cache.
company
Partial The result might supply partial queries, when Show me the revenue
per company is a subset
Query only a subset of the cached request is hit.
Cache
in columns of the logical
request above,
Show me the revenue
and sold quantities of
company 00001 is a
subset in rows of the
logical request above.
Table
The physical tables in the repository are
Cache physically cached as well. It's important to
understand that this has a great deal to do
with how current and real time data must be
and is dependent on how cache refresh is
scheduled.
Database
Cache
Not discussed on this page.
2
3
Reference: Oracle BI - Cache Management-v11-20131210_1236.docx
 Cadran Consultancy b.v.

3. Author
:
Project :
Contains :
1
Rick Brobbel
Oracle BIEE
Cache Management
Date printed :
Page :
Date :
10/12/13
3 of 12
10/12/13
Example:
2
3
Reference: Oracle BI - Cache Management-v11-20131210_1236.docx
 Cadran Consultancy b.v.

4. Author
:
Project :
Contains :
Rick Brobbel
Oracle BIEE
Cache Management
3
10/12/13
4 of 12
10/12/13
How it is setup
3.1
Date printed :
Page :
Date :
General Server Configuration
1
2
By default an Oracle BI installation will switch on the caching mechanism and starts using it with
default settings. This can be reviewed on the Oracle Enterprise Management console:
3
4
5
6
7
The parameters can be altered according to customer requirements and scaling based on the
number of users and reports.
These settings are stored in the NQSConfig.INI on the BI Server
(../instances/instance1/config/OracleBIServerComponent/coreapplication_obis1):
8
9
10
The comments also show where cache is stored on the BI Server:
Reference: Oracle BI - Cache Management-v11-20131210_1236.docx
 Cadran Consultancy b.v.

5. Author
:
Project :
Contains :
3.2
Rick Brobbel
Oracle BIEE
Cache Management
Date printed :
Page :
Date :
10/12/13
5 of 12
10/12/13
Server Parameters explained
Parameter
ENABLE
DATA_STORAGE_PATHS
MAX_ROWS_PER_CACHE_ENTRY
1
2
3
4
5
Default Explanation
YES
Switches caching on in the first place
Physical folder location
100.000 The maximum number of rows in the result
set of a query that is cached
MAX_CACHE_ENTRY_SIZE
20 MB The maximum size of the cache folder on the
server
MAX_CACHE_ENTRIES
1000
The maximum number of different queries
and result sets to be cached
POPULATE_AGGREGATE_ROLLUP_HITS NO
Set this to YES to activate smart roll up of
cache hits.
 For example a user requests all revenue
per month.
 The next user requests all revenue per
year.
The BI Server will aggregate the first
question to a higher level and answers the
second question.
USE_ADVANCED_HIT_DETECTION
NO
When caching is enabled, each query is
evaluated to determine whether it qualifies
for a cache hit. A cache hit means that the
server was able to use cache to answer the
query and did not go to the database at all.
The Oracle BI Server can use query cache to
answer queries at the same or higher level of
aggregation.
MAX_SUBEXPR_SEARCH_DEPTH
n/a
Undocumented feature that indicates how
deep this aggregation levels are evaluated
for rollup.
The three bottom parameters cannot be altered in the Enterprise Management Console. For this
you need to edit this file manually and then restart the BI Server.
Additional parameters become relevant when the BI Server is clustered over more servers. See for
more information this link.
Reference: Oracle BI - Cache Management-v11-20131210_1236.docx
 Cadran Consultancy b.v.

6. Author
:
Project :
Contains :
3.3
Rick Brobbel
Oracle BIEE
Cache Management
Date printed :
Page :
Date :
10/12/13
6 of 12
10/12/13
RPD Table Caching
1
2
Physical tables are by default not cached when mapped in the repository. When a table is created
or imported from metadata one has to deliberately switch on caching:
3
4
5
6
7
8
9
Mark the check box and setup the cache persistence time. For static tables such as companies this
might be set to a longer period. More dynamic tables with transactions can be set to shorter
periods. As soon as this table is queried upon by the BI Server and the database has returned the
results, it is cached and will stay there until the cache persistence expires or the cache is cleared
(see below).
Tables that supply real time data can be left unchecked.
10
Reference: Oracle BI - Cache Management-v11-20131210_1236.docx
 Cadran Consultancy b.v.

7. Author
:
Project :
Contains :
Rick Brobbel
Oracle BIEE
Cache Management
4
10/12/13
7 of 12
10/12/13
How it is managed
4.1
Date printed :
Page :
Date :
Viewing the cache
1
In the BI Client Admin Tools connect to the online repository and choose Manage - Cache:
2
3
Select the bottom tab Physical to view physical table caching:
4
4.2
Clearing the cache
5
6
7
8
Especially during test and development phase caching might be in the way because you cannot
directly see results of changes or in the source data. During this phase you might switch caching
off. If you want to delete the cache (partially) you can do so from this utility in the BI Client Admin
Tools:
9
10
Reference: Oracle BI - Cache Management-v11-20131210_1236.docx
 Cadran Consultancy b.v.

8. Author
:
Project :
Contains :
4.3
Rick Brobbel
Oracle BIEE
Cache Management
Date printed :
Page :
Date :
10/12/13
8 of 12
10/12/13
Scheduling cache clearing
1
2
3
In a real live situation the cache might be cleared periodically (for instance every day early in the
morning).
This requires the following setup:
Step
Screen print
Create a Database in the RPD
In the BI Model create a ODBC-connection-pool
that matches the ODBC-connection on the local
PC that runs the BI Client Admin Tools as well
as the ODBC-settings on the BI Server (see
OBIEE Server for this):
Check in the repository to the BI Server
Reference: Oracle BI - Cache Management-v11-20131210_1236.docx
 Cadran Consultancy b.v.

9. Author
:
Project :
Contains :
Rick Brobbel
Oracle BIEE
Cache Management
Step
On the BI Web Client - New - Create Direct
Database Request
Date printed :
Page :
Date :
10/12/13
9 of 12
10/12/13
Screen print
Enter "BIServer"."AnalyticsWeb" in the
Connection Pool
Enter Call SAPurgeAllCache(); in the SQLstatement (this is an ODBC nQSCommand that
does the job).
Press Validate SQL and Retrieve Columns to
see the Result Columns.
Click tab Results (this clears the cache directly
because this command is now executed).
This Analytics can now be stored, put on a
System Administration dashboard for manual
execution and be scheduled periodically using
an Agent.
1
2
Reference: Oracle BI - Cache Management-v11-20131210_1236.docx
 Cadran Consultancy b.v.

10. Author
:
Project :
Contains :
4.4
Rick Brobbel
Oracle BIEE
Cache Management
Date printed :
Page :
Date :
10/12/13
10 of 12
10/12/13
Scheduling cache population
1
2
3
4
5
6
Every user that touches a dashboard or an analytics will populate the cache with this information.
That means that this user will have to wait. A next user will use seeded cache and therefore will
have a much faster response.
By scheduling these dashboard pages by Agents the population of the cache can be done
automatically. Make sure that these Agents are scheduled after the Agent that clears the cache .
When an Agent is setup a special checkbox in the Destinations tab is used for this:
7
8
9
Set the Delivery Content to the appropriate Dashboard Page and create similar agents for all the
separate dashboard pages that need preloading:
10
11
12
The delivery content, format and destination are irrelevant for these kind of agents.
Reference: Oracle BI - Cache Management-v11-20131210_1236.docx
 Cadran Consultancy b.v.

11. Author
:
Project :
Contains :
4.5
Rick Brobbel
Oracle BIEE
Cache Management
Date printed :
Page :
Date :
10/12/13
11 of 12
10/12/13
Bypassing cache
1
2
3
When an analytics must always access the database because real time data is required, the cache
can by bypassed.
To realize this do the following:
Step
Screen print
Edit the Analysis and go to the Advanced tab
and check the box Bypass Oracle BI
Presentation Services Cache.
This takes care of not using the BI Presentation
Cache.
Scroll down to the section Advanced SQL
Clauses
Enter SET VARIABLE
DISABLE_CACHE_HIT=1; in the Prefix and
press Apply SQL
This takes care of overriding the physical table
cache.
Click OK on the warning
Note that this code has now been added to the
SQL-statement
Save the Analytics and it will bypass all caching
4
5
Reference: Oracle BI - Cache Management-v11-20131210_1236.docx
 Cadran Consultancy b.v.

12. Author
:
Project :
Contains :
5
Rick Brobbel
Oracle BIEE
Cache Management
Date printed :
Page :
Date :
10/12/13
12 of 12
10/12/13
Additional notes, tips & tricks
1
2
3

4
5
6
7
8
9
10
11
12
13

14
15
16
17
18

The cache folder as well as temp folders on the BI-server get corrupted with old data and leave
behind garbage. The Clear Cache command does not physically remove all these folders.
System Administration will have to see about cleaning up every once and a while.
Setting up a smart combination of datawarehouse tables with historical data and real time data
it is possible to optimize performance when high volume data is involved. For instance when
the JD Edwards General Ledger (F0911) is a source for Finance Analytics this method can
help. Creating a fragmented data source that might have three sources creates the optimal
combination of very accurate and real time data with using the power of datawarehousing and
the BI model:
o All data onto the end of last month is coming from a datawarehouse or staging area;
o All data from the start of this month onto yesterday is coming from the sourcedata and
is cached;
o All data from today is coming directly from the datasource without caching;
...
More information will follow as we go along.
Reference: Oracle BI - Cache Management-v11-20131210_1236.docx
 Cadran Consultancy b.v.