OBIEE Blog

A. “Ago function returning wrong results in answer when comparing this year versus last year” This actually happened to me once – and i thought it was an incorrectly configured time dimension. You can experience this error when your “Time Series functions gives incorrect results when leap years are involved”. Oracle support suggested the following action plan :

1) Leave the logical column definition as earlier i.e. Ago(Measure, Year, 1)
2) Change the filter condition in the request to filter on year and months instead of date range e.g.
year = 2009 and month in (1,2,3,4)

B. “Value Suppression doesn’t work for Level Based Measures”. Someone had a requirement where they wanted to use level-based measures for reports accessing several fact tables in the future. To realize a prototype before starting with the necessary reports they tried to implement an easy example to test the ‘value suppression’ functionality

Unfortunately they are not able to build a nice looking report with four simple columns showing the year, # of orders (per year), quarter and # orders. Their problem is that the level based measure ‘# of order (per year)’ is shown line by line. They wanted to suppress these values and only show the value once per year. They tried to use the ‘value suppression functionality’ without success. They were able to Work around this issues by using a Pivot Table.

C. This issue in pivot table is very common –

OBIEE says “governor exceeded error”. The pivot tables and the charts might give these errors:

Error Generating Chart
An exception occurred in the cube.
Error Details
Error Codes: MOJ5XVNL:QBVC92JY
Governor limit exceeded in cube generation (Maximum data records exceeded.)

and for pivot table

View Display Error
Governor limit exceeded in cube generation (Maximum data records exceeded.)
Error Details
Error Codes: QBVC92JY

Theses messages mean that users are trying to return more rows to the pivot table then the governor will allow. One needs to adjust the following parameters until the report runs successfully.

Adjust the parameters below in instanceconfig.xml (add those tags if you don’t have them – since those values are by default) and then restart Presentation Server (sawserver)

< CubeMaxRecords >40000< /CubeMaxRecords >
< CubeMaxPopulatedCells >150000< /CubeMaxPopulatedCells >

Someone asked the Oracle support if Siebel Analytics could use 2 LDAP servers for authentication. “We currently use one of the LDAP server for authentication and it works fine. We have some users from another LDAP server and want to add it to our authentication.”

Response was:
Siebel Analytics can only authenticate against on LDAP server at a time. If you define multiple LDAP servers, the 2nd LDAP server is not being looked at unless the connection to the 1st failed.

You define multiple LDAP server by putting the LDAP server names in a concatenated string and use space as delimiter in the Host Name entry, i.e. “ldap1.siebel.com ldap2.siebel.com:9872 ldap3.siebel.com” in AN78x release

In the latest Oracle Business Intelligence Enterprise Edition, you can define multiple LDAP server definitions in the Manage > Security > LDAP Server.

But Authentication tries the first LDAP server, if it fails then it uses the second LDAP server defined in the repository

“Product change request 12-HOAZ87 has been logged to ask for authentication against multiple LDAP servers simultaneously.”

The cache is purged but new cache is not created. Customer is not able to cache the reports which contain Database Functions for Columns.
All the cache entries were not created when used a logical query which contains DB functions in it. The query doesn’t get cached and there is no error
produced.
Cache is created when the queries are not using any database functions.

Cause

Queries containing the evaluate function are not qualified to cache. Hence this query is not getting cached. This is expected behavior.
Evaluate is not cacheable because there is no reliable means for OBIEE to interpret the semantics of the string function definition and determine if the
function defined there can be reused under what condition. Take a simple example, Evaluate(‘Today()’ as Date), OBIEE would have no idea this function
returns a result that can be reused till the end of day.

Dynamic repository variables are refreshed by data returned from queries. The same rule applies here. If the query that refreshes the variable is using a
database function and evaluate then the whole query (report) will not be cached as the value of the variable cannot be cached.
If the query that refreshes the variable does not use database functions then it is cached and the report should be cached.
However, when the value of a dynamic repository variable changes, all cache entries associated with a business model that reference the value of the variable,
are purged automatically.

If you see the query in the Cache Manager then it means that is cached. You can check if that particular cached query is used or not by checking the “Last
used” column after the user ran the report. The cache should be used and the value of the “Last Used” column should be updated and different from the value
of the “Created” column.

Solution
Using iBots is an alternative. If you schedule the reports they should appear in the cache until the cache is purged. Keep in mind that reports having the
database functions and evaluate will not be cached either. Also, reports having dynamic repository variables will automatically be purged when the variable
changes.
The iBot should not include queries with database functions and evaluate in order to be cached.

I found an interesting bug in metalink. I wish there were more specifics as to how complex the report was. I just had a similar Assertion error yesterday which I tried to solve by increasing STACK size. However, it seems as it’s possible to crash BI server with longer reports.

When a custom report is executed on Windows the following error is received: -

Error Codes: OPR4ONWY:U9IM8TAC:OI2DL65P
State: HY000. Code: 10058. [NQODBC] [SQL_STATE: HY000] [nQSError: 10058] A general error has occurred. [nQSError: 46036] Internal Assertion: Condition FALSE, file .\NQThreads\SUGThread.cpp, line 515. (HY000)

However, on Linux the OBI Server crashes with this typical Stack Trace from the Core file generated: -

0 0xb427f9b2 in samem_details_800::ThreadAllocator<0>::Allocate
(this=0x86fcd00, Index=2) at threadallocator.cpp:443
443 { (gdb) bt
#0 0xb427f9b2 in samem_details_800::ThreadAllocator<0>::Allocate
(this=0x86fcd00, Index=2) at threadallocator.cpp:443 @ #1 0xb42784df in samem_details_800::ThreadAllocator<0>::allocate
(this=0x86fcd00, nBytes=20, nIndex=2,
pFile=0xb4a171dc “thirdpartysource/STLport-4.5/src/nqnodealloc.cpp”,
nLine=10) at threadallocator.cpp:966
#2 0xb4286098 in samem_details_800::Manager::Allocate (this=0xb429cac0, @ Bytes=20,
pFile=0xb4a171dc “thirdpartysource/STLport-4.5/src/nqnodealloc.cpp”,
nLine=10) at manager.cpp:469
#3 0xb4283dae in samem_800_allocate_dbg (Bytes=20, pFile=0xb4a171dc @ “thirdpartysource/STLport-4.5/src/nqnodealloc.cpp”, nLine=10)
at memoryallocator.cpp:160
#4 0xb49fbfb8 in NQNodeAlloc::allocate (__n=20) at @ thirdpartysource/STLport-4.5/src/nqnodealloc.cpp:10
#5 0xb721a1f3 in _SASSTL::allocator<_SASSTL::_Rb_tree_node
>::allocate (this=0x87f7bac, __n=1)
at thirdparty/include/stlport/stl/_alloc.h:372
#6 0xb721a02e in
_SASSTL::_STLP_alloc_proxy<_SASSTL::_Rb_tree_node*,
_SASSTL::_Rb_tree_node,
_SASSTL::allocator<_SASSTL::_Rb_tree_node > >::allocate @ (this=0x87f7bac, __n=1)
at thirdparty/include/stlport/stl/_alloc.h:514
#7 0xb72198c6 in _SASSTL::_Rb_tree, _SASSTL::less, @ _SASSTL::allocator >::_M_create_node (this=0x87f7bac, @ __x=@0xb0e23264)
at thirdparty/include/stlport/stl/_tree.h:243
#8 0xb673169d in _SASSTL::_Rb_tree, _SASSTL::less, @ _SASSTL::allocator >::_M_insert (this=0x87f7bac, __x_=0×0, @ __y_=0x8d895b8, __v=@0xb0e23264, __w_=0×0)
at thirdparty/include/stlport/stl/_tree.c:366
#9 0xb6730c6d in _SASSTL::_Rb_tree, _SASSTL::less, @ _SASSTL::allocator >::insert_unique (this=0x87f7bac, @ __v=@0xb0e23264)
at thirdparty/include/stlport/stl/_tree.c:412
#10 0xb6730499 in _SASSTL::set, _SASSTL::allocator >::insert @ (
this=0x87f7bac, __x=@0xb0e23264) at
thirdparty/include/stlport/stl/_set.h:137
#11 0xb672fe6b in RqNode::AddRqNodePtr (this=0x87f7b88, pRqNodePtr=0x8d999e8)
at server/Query/Optimizer/Request/Src/SQORRqNode.cpp:432
#12 0xb672e34e in SmartRqNodePtr (this=0x8d999e8, rhs=@0x8d995a0) at @ server/Query/Optimizer/Request/Src/SQORRqNode.cpp:55
#13 0xb66a7d17 in RqDerivedColumnReference (this=0x8d999b8, rhs=@0x8d99570, @ bNewIDs=false, bDeepCopy=true)
at server/Query/Optimizer/Request/Src/SQORRqExpr.cpp:1418
#14 0xb66a8898 in RqDerivedColumnReference::DeepCopy (this=0x8d99570, @ bNewIDs=false)
at server/Query/Optimizer/Request/Src/SQORRqExpr.cpp:1525
#15 0xb672e748 in RqNode (this=0x8d977b0, rhs=@0x8d97368, bNewIDs=false, @ bDeepCopy=true)
at server/Query/Optimizer/Request/Src/SQORRqNode.cpp:146
#16 0xb66a0d3c in RqExpr::RqExpr$base () at @ server/include/Query/Optimizer/Request/SQORRqNode.h:77
#17 0xb66d0f68 in RqExprCond::RqExprCond$base () at @ server/include/Query/Optimizer/Request/SQORRqList.h:33
#18 0xb66d6c58 in RqExprCondIsNull (this=0x8d977b0, rhs=@0x8d97368, @ bNewIDs=false, bDeepCopy=true)
at server/Query/Optimizer/Request/Src/SQORRqExprCond.cpp:1299
#19 0xb66d6e88 in RqExprCondIsNull::DeepCopy (this=0x8d97368, bNewIDs=false)
at server/Query/Optimizer/Request/Src/SQORRqExprCond.cpp:1342
#20 0xb672e748 in RqNode (this=0x8d8f878, rhs=@0x8d8f430, bNewIDs=false, @ bDeepCopy=true)
at server/Query/Optimizer/Request/Src/SQORRqNode.cpp:146
Cause
It appears that due to the complexity of the Expressions in the Answer Columns of the custom Report, the Expression Builder makes several recursive calls which eventually increases the Stack Size of the Thread until it reaches its maximum and it throws an Asertion Error.

On a Windows environment we have a check of the ‘LowStackCheck’ parameter which is not present in Linux and therefore it crashes the OBI Server giving a ‘sigsegv’ error.
Solution

Currently, there is no solution. The workaround is to re-design the report so that the Expressions are less complicated (e.g. Creating Measures that sum up at various combinations of Dimension Levels that allows the Users to avoid creating the complex Formulas in Answers and performs well)

This looks like a major change in the code is required to fix this type of behavior and therefore we will not be able to fix this until at least our 11.x release.

Found something interesting about cache today.

Symptoms

Have a report in Answers.
For one of the values (Jan09 / Budget) the value is 10,000.
Value in database is updated to 600,000
Looking at the report in Answers, it still displays the amount for this value as 10,000.  This happens even after selecting ‘Refresh’ for the report.

If the user drills into Jan09, & so views each week of Jan09, then the value can be seen as 600,000. Drill back out to Jan09 & again it is displaying as 10,000 (the original value).

Turning off caching (in NQSConfig.INI with [ CACHE ] ENABLE =NO ) DOES fix the issue. However, this causes performance issues.
Cause
In fact, this is working as designed.

As per Answers guide, this is expected behavior:

“When executing an Oracle BI Interactive Dashboard or a request, Oracle BI uses temporary storage areas, called caches, to save frequently accessed or recently accessed results. Storing certain results in cache helps to improve Oracle BI performance. You can use the Refresh feature to make sure that your request bypasses saved information in the Oracle BI Presentation Services cache and is issued to the Oracle Business Intelligence Server for processing. NOTE: The Oracle BI Server maintains its own cache. This cache is separate from the Oracle BI Presentation Services cache.”

So, the ‘Refresh’ link only bypasses the OBI Presentation Services cache and the request is issued to the Oracle Business Intelligence Server for processing. It does not bypass OBI Server cache. If the BI Server cache is enabled the request hits the BI Server cache and you then see the old data.

It will not bypass the BI Server cache and will only satisfy your request (and fire the SQL to database) if there is no BI Server cached results.
Solution

The BI Server cache should be cleared to fix the issue.