No of elements in a logical level.

Hi
I am very much confused with the following one. How do we know that there should be some "n" number of elements in one logical level?
"No of elements at this level......." ?
Thanks&Regards
Suresh.

Hi Kishore
thank you very much for your answer. I was searching this on google for the past one month and all searches went in vain.
But your answer is extremely valuable.
Thank you very much and keep it up.
Thanks&Regards
Suresh.

Similar Messages

Number of elements at logical level / odbc driver

Hi everyone,
I'm new in BI area and I cannot understand one basic thing.
I study documentation about BI server, exactly chapter about "creating dimensions" and I'm confused about setting "number of elements at logical level"
It looks for me that "number of elements at logical level" is static.
What will be when someone update data in the table and number of elements will be different than number of elements in our logical level?
example:
current column with distinct values:
channel_desc:
direct sales
tele sales
catalog
internet
partners
in this case I set number of elements at logical level 5.
after a while some update data in the table and our column looks (see below)
column after update with distinct values:
channel_desc:
direct sales
tele sales
catalog
internet
partners
others (added value)
Does it mean that I have to change it to current numbers of elements?
I'm sure that this is misunderstanding in my case, but I don't know where?
Second problem which I have:
BI with oracle database is on linux
client software on windows
I can import data from database like sybase or flat files to the physical model, I can view data, but when I create whole model (physical, bussines model and mapping, presentation) and I try access data from "Answers" I have this error:
"Data source name not found and no default driver specified"
regards
Bart

Number of elements is just an indication used by the BI Server (e.g. when generating LOV's in Answers). It won't cause any problems when it doesn't hold the exact number of elements available in the dataset.

Number of elements to be defined at logical level

In the Business Model and Mapping layer, dimension >Logical Level >> number of elements at this logical level
I have come across two different version of how to deal with this
First version - From the OBE and the admin server guide it says "The number does
not have to be exact, but ratios of numbers from one logical level to another should be accurate".
Second Version - a question from asked about what defines the number at the level as best practices
To set the number of elements at each level of a dimension, which number would you use?
A. the number of columns in a logical table
B. the number of levels in a dimension
C. the number of dimensions in a business model
D. The number of tables in a physical model
E. the number of distinct rows in physical column
Question is
what is the rule to set the number of elements at this level?
If its been set depending upon the rows in the table . what will happen if the rows gets added every hour ??
Edited by: ZSAM on Jun 8, 2011 7:06 AM
Edited by: ZSAM on Jun 8, 2011 8:22 AM

The ratio between the levels is what is important I believe. BI Server will use this information to determine which aggregate source to use. You should use the number of distinct rows as the value.
You can also right click the hieracny and use "Estimate Levels" to auto-populate the numbers for you.
Paul

Use of New logical Level Key in OBIEE

Hi all,
can anybody tell me what is the use of newlogicallevel key in hierarchies(OBIEE).
why we need to set a newlogical level key for each level in hierarchies.
pls explain in detail....
regards
bharath

You may get info as below if you use Admin tool help file
Level keys. Each logical level (except the topmost level defined as a Grand Total level) needs to have one or more attributes that compose a level key. The level key defines the unique elements in each logical level. The dimension table logical key has to be associated with the lowest level of a dimension and has to be the level key for that level.
A logical level may have more than one level key. When that is the case, specify the key that is the primary key of that level. All dimension sources which have an aggregate content at a specified level need to contain the column that is the primary key of that level. Each logical level should have one level key that will be displayed when an Answers or Intelligence Dashboard user clicks to drill down. This may or may not be the primary key of the level. To set the level key to display, select the Use for drill down check box on the Level Key dialog box.
Be careful using level keys such as Month whose domain includes values January, February, and so on—values that are not unique to a particular month, repeating every year. To define Month as a level key, you also need to include an attribute from a higher level, for example, Year. To add Year, click the Add button in this dialog and select the logical column from the dialog that is presented.

Doubt regarding No. of elements at a particular level of a dimension

Hi,
What does the No. of elements at a particular level of a dimension indicate?How do you calculate it? Suppose we have 10 years data and the time dimesion levels goes as Year----Quarter----Month----Date what would be the no of elemets at each level?
Kindly post a reply at the earliest.

Hi..
see my reply here..
no of elements in a logical level.
Regards
Kishore Guggilla

If Logical level mappings are blank in an LTS , what does it mean?

Hi All,
I was trying to find this out in the forum but couldn't.
In my LTS, on the content tab, if i don't specify any "Aggregation, group by" information for the dims associated with my Fact table and keep it blank, then what does it mean? Would OBIEE treat this as at the detail level by default? So to test this, I created a logical fact and for its LTS, i didn't associate any logical level for dimensions. The query didn't give me any error and worked fine by using the correct join details.
Also when do we associate an LTS with the Total Level for a dim, what's the use because as I understand, this means all our measures from that LTS would be calculated for the total level of the dim and we can do this by creating level based measure and associating it with the total level of the dim.
I'll be thankful if somebody could explain me this in detail or direct me to a relevant documentation/ blog
Thanks,
Ronny

Hi,
When you have only one logical Table Source(LTS).
You don't specify the logical levels. By default it would consider the detail level of the logical levels mapped to the fact table.
When you have Multiple logical Table Source(LTS).
The concept of Multiple LTS comes into picture when you have multiple sources. The BI server picks the optimum logical source depending upon the fields (columns) selected. And also depends on the Number of element set while creating the dimension hierarchies. Refer-http://gerardnico.com/wiki/dat/obiee/level_number_element
For example- Suppose you have two logical table source Fact 1 and Fact 2 and logical levels( dimension hierarchies are created for two dimensions Dim 1 and Dim 2).
For the first Fact 1 source logical level is mapped only with Dim 1 and Fact 2 is mapped to Dim 2.
(You need to decide which fact source to hit depending upon the dimensions used in the report.)
Then in the report when you select Dim 1 (by means of column selector/filters) then Fact 1 source will be hit and same appears in the query.
Then in the report when you select Dim 2 (by means of column selector/filters) then Fact 2 source will be hit and same appears in the query.
One more situation where you have mapped Fact 1 with Dim 1 First level of aggregation and Fact 2 with Dim 1 with Detailed level. Then the BI server picks depending upon the user's request. If the request data can be pulled from the detailed level ( which tends to be optimum then picks from the second source).
So, its always better to set the logical source and check the query, if its hitting the correct sources according to the requirements.
Regards,
MuRam

Regarding Logical level key and row wise initialization

Hi Gurus,
What is the purpose of row wise initialization in external table authentication and when we have to go for row wise initialization.
Why we have to enable logical level key in hierarchy is this only for getting drill down to the next level if we make two columns as logical level key what will happens. If we want to enable a column as a logical level key what are the character sticks that column should satisfy.
Thanks,

1) Row Wise Initialization used to hold multiple values in a variable. Let says SQL gives 4 rows (A,B,C,D) as output. Now I want to hold 4 value in a variable to get this happen we need to go for RowwiseIniziation. If you do not do this at any point in time Variable holds only value A not others. Simply it works as Array.
2) Level keys define the unique elements in each level and provide the context for drill down. You can make two logical columns as logical key but you need to make sure what to be displayed in your hierarchy by selecting DISPLAY. If you make to as separate logical keys and set Display for both you get two columns in the hierarchy
http://gerardnico.com/wiki/dat/obiee/hierarchy_level_based

Logical Level in Content Tab

Hi,
What is the use of Logical Level under Content Tab in Logical Table Source?
Need more information, docs related to this
Thanks,
Satheesh

Hi
This logical level is useful for level bases metrics.It shows the levels in your hierarchy.We can give the level in this and in the report it shows the data for that level only.
See this lnk, http://gerardnico.com/wiki/dat/obiee/measure_level_based
Thanks
Don

Logical level in Fact tables - best practice

Hi all,
I am currently working on a complex OBIEE project/solution where I am going straight to the production tables, so the fact (and dimension) tables are pretty complex since I am using more sources in the logical tables to increase performance. Anyway, what I am many times struggling with is the Logical Levels (in Content tab) where the level of each dimension is to be set. In a star schema (one-to-many) this is pretty straight forward and easy to set up, but when the Business Model (and physical model) gets more complex I sometimes struggle with the aggregates - to get them work/appear with different dimensions. (Using the menu "More" - "Get levels" does not allways give the best solution......far from). I have some combinations of left- and right outer join as well, making it even more complicated for the BI server.
For instance - I have about 10-12 different dimensions - should all of them allways be connected to each fact table? Either on Detail or Total level. I can see the use of the logical levels when using aggregate fact tables (on quarter, month etc.), but is it better just to skip the logical level setup when no aggregate tables are used? Sometimes it seems like that is the easiest approach...
Does anyone have a best practice concerning this issue? I have googled for this but I haven't found anything good yet. Any ideas/articles are highly appreciated.

Hi User,
For instance - I have about 10-12 different dimensions - should all of them always be connected to each fact table? Either on Detail or Total level.It not necessary to connect to all dimensions completely based on the report that you are creating ,but as a best practice we should maintain all at Detail level only,when you are mentioning any join conditions in physical layer
for example for the sales table if u want to report at ProductDimension.ProductnameLevel then u should use detail level else total level(at Product,employee level)
Get Levels. (Available only for fact tables) Changes aggregation content. If joins do not exist between fact table sources and dimension table sources (for example, if the same physical table is in both sources), the aggregation content determined by the administration tool will not include the aggregation content of this dimension.
Source admin guide(get level definition)
thanks,
Saichand.v

Setting aggregation content for logical level in 11g

Hi Guys,
When working on with horizontal and vertical federation in OBIEE 11g with multiple data sources here in my case it is essbase and RDBMS.
1) pulled the columns and dragged into the concerened table.
2) The related heirarchies have been defined.
3) when trying to go to one of the LTS and trying to set the logical level aggregation im not able to see the levels columns corresponding nor im getting the get levels option to get them. where am i going wrong?
when im trying to join a fact by pulling it on to the fact...i can see the levels in content tab,but when i try to define levels and check it its giving me error "There are no levels matching the BI algorithm"
Any answers wud be appreciated.
TIA,
KK
Edited by: Kranthi.K on Sep 5, 2011 2:52 AM

It is autocreated,i dint customize it.....Im dropping the RDBMS table onto the Essbase cube dimension table and im not getting the RDBMS content levels that should be defined in the LTS of the table,and the RDBMS table has an level based hierarchy but still no sucess.
Any more ideas
UPDATED POST
Deepak,it was not helpful as i have gone through tht document before....Im trying it in all scenerios to figure out where actually it is going wrong.
If i dont find the path,i will let you kne what im trying to do so you can help me out.
UPDATED POST-2
Any more pointers from the experts.
Edited by: Kranthi.K on Sep 6, 2011 7:01 AM

Setting Logical Level in LTS

Hi all,
Usually we set the Logical Level (Content Tab) for the LTS in the Fact table.
Is there any best practice to set it for the LTS in Dimension tables too? If yes, why do we do that?
Please clarify on this. This is very urgent.
Regards.

one thing is If you have multiple LTS in a single dimension like detail dim and aggregated dim. then you have to set the content levels for each LTS. Its always a good practice to mention which level the dimension is in any case.

Help on Setting logical Levels in Fact tables and on Dimension tables

Hi all
Can any body provide any blogs or any king of material on what exactly is levelling .
Like after creating the Dimensional hierarchies we need to set the logical levels for the LTS of fact tabels ri8 .So what is the difference between setting logical levels to fact tabels and also Setting levelling on Dimension tables .
Any kind of help is appreciated
Thanks
Xavier.
Edited by: Xavier on Aug 4, 2011 10:50 AM

I have read these blogs ,but what my question is
Setting the logical levels in LTS of Fact tables i understood .
But we can also set the logical levels for dimensions also ri8 .I didn't understand why do we set the logical levels for dimensions .Is there any reason why we go with the levelling at dimensions
Thanks
Xavier
Edited by: Xavier on Aug 4, 2011 2:03 PM
Edited by: Xavier on Aug 4, 2011 2:32 PM

Logical level for logical fact table sources

it is clear that for fact aggregates, we should use the Content tab of the Logical Table Source dialog to assign the correct logical level to each dimension.
question is : is it mandatory to assign even for non-aggregates fact tables the logical level for each dimension (which normally should be set to the most detailed level of each dimension) ? is it any known issue if "logical levels"in content tab are not set ?
the reason I'm asking this is a strange bug I have (I'm not going to discuss it here) and then only workaround seems to be NOT setting the logical levels (on content tab) for logical fact table sources.
thank you !

If levels are not set: By default levels are considered as lowest level
It should not matter if you set or not
Generally we set for facts explicitly when we are using Aggregate tables.
Your current issue might be a case by case; I would suggest to check implicit fact, any table mapped to the source to force a join etc
Mark if helps
Let me know how it helps
Edited by: Srini VEERAVALLI on Feb 5, 2013 8:33 AM
Any updates on this?+_
Edited by: Srini VEERAVALLI on Feb 14, 2013 9:09 AM

Logical Difference of defining Multiple Logical level keys

Hi All,
We add logical level keys in BMM layer by right cliking the logical level column of a dimesional hierarchy, doing so defines a new logical key, i already have another logical level column defined as logical level key.
When i double click on logical level hierarchy, it has keys tab where i have two keys now.
say the two keys are: "channel desc key" and "channel id key"
My question is in one key say "channel id key" if we click edit, i am getting all the columns including channel desc column, so if i click it as key, it forms a composite key of (channel id) + (channel desc) inside "channel id key". Then what is the use of maintaining another key = "channel desc key"
Is there any logical difference of ("maintaining two keys having single column defined as key in either of them") and ("maintaining one key having two logical columns defined as keys in a single logical level key")?
Thanks in Advance.
Regards,
Sreekanth.

Hey got the answer, there is a difference, if i add multiple columns as keys under a single logical level key, they both come under one key and its drill down on both the columns, i cannot select selectively out of which column of the two drill down is applicatble.
If i create two different logical keys for two columns i can selectively choose which column drill down is applicable to.
Drill Down is based on "Logical Level Key" not on Logical Level Column selected as key.
Thanks,
Sreekanth.

Logical level Dimensions

Hi,
I am setting up a new heirarchy in Business level RPD, and in the new "Dimensions", the tab "Tables" is disabled, i tried opening it in both online as well as offline mode, same issue.
When I add a new "Logical Level" object under it, the "Add" child level key is also disabled. Please help.
Thank you.

hi,
when you create new dimension, by default the "tables" tab will be disabled because there are no tables in the dimension. and if you give right click on the new dimension it shows only logical level because there must be atleast one level to create the child and parent levels.for that you just select the columns from the dimension table and drag them into the logical level created in the dimension. and now the parent level and child level will be enabled.this is the process to create the hierarchy if you select "create new dimension" instead of this you can directly go to the dimension table in the BMM and give right click and select create dimension option. this will create the dimension hierarchy.
hope you understood...

No of elements in a logical level.

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