Aliases in physical layer

we have created aliases for all the tables.we have joined the alias tables, way it is in the data model.
now do i need to drag all the tables and aliases from physical layer to business layer?
now we already join the alias tables and do in need to join the physical tables again?
can you explain elabarately....is there any reason of using the aliases for all the tables?
what is the benifit of creating aliases for all the tables.

Once you created your alias tables, it is a best practice to use this for the joins. Thus, there is no need to join your original physical tables.
Alias have a lot of advantages like:
1. reusing the same physical table more than once to create an alias and create a completely new join
2. you can setup multiple alias tables with different keys or joins
3. used to convert the ER schemas to dimensional schemas in designing star/snowflake schema

Similar Messages

BMM layer creation (Star Schema Physical Layer) - What to add/not add?

Hi All,
I am just looking for any general feedback on the thought/question below.
I am setting out on creating my first BMM layer and trying to determine what I need to do in this layer that will be different and add value from what I already did in the physical layer. My data model is already defined as a star schema within my data mart source. So in the physical layer I have my facts imported along with the dimensions and I have joined them together as needed. Here is what I think I will setup as I move into the BMM layer:
1. I will add heirarchies as needed to enable drill down within my reports
2. I will need to add my calculations/measures to allow for any type of metric to be returned through a request in Answers
3. I do not see a large need to create logical tables (at least not yet) based on multiple physical source tables as my source is already a star schema and dimensionally modeled. For users that also already source a star schema at the physical layer .. do you find that you do a lot of logical table creation/mapping to add functionality or does your BMM look a lot like you Physical Layer?
Other than steps 1 and 2, I am not really sure how much additional manipulation I might do from the Physical to BMM layer since my Physical is already a star schema. Am I missing anything? Obviously everyone's data model and circumstances are different but I wasn't sure if maybe there were some good thoughts on what I might be missing (if anything)?
One last question .. I am not currently planning to use any aliases at the Physical Layer but I do plan to rename the tables at the presentation layer to be more business verbage like. Why are others using aliases?
Thanks in advance for the help.
K

Alastair, thanks for the advice. I'll definitely keep that in mind as I start to build out the BMM.
One question/issue I just ran into as I was wrapping up my Physical Layer mapping. When I check for global consistency, I am getting an error that is complaining that I have multiple joins defined between the same two tables (which I do). This is because I have the following setup:
TBL_A_FACT
F_ID_HIT
F_HIT_DESC
F_ID_MISSED
F_MISSED_DESC
TBL_B_DIM
F_ID
F_DESC
Table A joins to Table B in two ways:
TBL_A_FACT.F_ID_HIT = TBL_B_DIM.F_ID
TBL_A._FACT.F_ID_MISSED = TBL_B_DIM.F_ID
The F_IDs can be either hit or missed on any given fact record and the total distinct set exist in the dimension.
When I define two foreign key joins in the physical layer based on the relationship above and check Global Consistency, I get an error saying that "TBL_A and TBL_B have multiple joins define. Delete duplicate foreign keys if they exist" and it is listed as an error. I guess this makes sense because when the two tables are used in a request OBIEE would need to know how to join them (using the hit or missed field). What is the best approach for handling this..
- Should I define TBL_A twice in the physical layer as:
TBL_A (Alias TBL_A_HIT)
F_ID_HIT
F_ID_HIT_DESC
TBL_A (Alias TBL_A_MISSED)
F_ID_MISSED
F_ID_MISSED_DESC
Or do something like the above in the BMM layer?
Thanks for the help!
K
And then establish the relationships using these separate tables?

Duplicate table and Alias table in the physical layer

Hi,
I want a clear information regarding the duplicate tables in the physical layer of the rpd.
I mean what is the purpose of the duplicate tables in the physical layer.........
thanks,
chinna.

what do you mean by duplicate of physical table? is it Alias table?
if then,
-> aliases are created to break the circular joins (which are not supported by obiee)
-> and, as per apps standards no operation can be done on base tables which are imported directly to physical layer. Only aliases are joined and will be used in BMM layer
-> useful to re-use the table more than one time , best example: W_DAY_D in apps rpd
Edited by: Kishore Guggilla on Sep 23, 2010 10:41 PM

Alias Tables and Duplicate tables in Physical Layer

Hi all,
I have a small doubt in physical layer. We have two options when we right click table, 'Alias' and 'Duplicate'. To create another instance of a table, can we use any one of these. Does it make any difference
Thanks & Regards,
Jagi

Hi,
If u duplicate any table the join conditions will carry with respective tables , same name appending (TableName#1)
In case of alias u need to specify joins conditions explicitly
We can use same table with different constrains to the same table
Aliases used, if you need to replicate a physical table and not create multiple tables with the same data
If you delete any column in the Original table automatically deleted in alias
table and Its not reflected in Duplicate table.
Steps:
Right Click the original table. Choose New Object and choose Alias.
The mistake most people make is try to bring in the same table again and rename it or choose Duplicate by right clicking the original table.
Thanks,
Balaa...

Obiee - physical layer

Hi,
I'm new to obiee tool.
my dimension table have composite primary keys (3 keys - suppose employee id, employee ssn, phone no)
and my fact table have (2 keys - employee id, employee ssn )
then, how do we do physical join in physical layer ?
Do, we need to create 2 alias tables and join to my fact table ?
or, else can i use expression builder in the physical diagram..physical join ?

Hi,
This is why you go for alias tables ..
To set up multiple tables, each with different keys, names, or joins, when a single data source table needs to serve in different semantic roles. Setting up alias tables in this case is a way to avoid triangular or circular joins.
For example, an order date and a shipping date in a fact table may both point to the same column in the time dimension data source table, but you should alias the dimension table so that each role is presented as a separately labeled alias table with a single join. These separate roles carry over into the business model, so that "Order Date" and "Ship Date" are part of two different logical dimensions. If a single logical query contains both columns, the physical query uses aliases in the SQL statement so that it can include both of them.
You can also use aliases to enable a data source table to play the role of both a fact table, and a dimension table that joins to another fact table (often called a "fan trap").
To include best practice naming conventions for physical table names. For example, you can prefix the alias table name with the table type (such as fact, dimension, or bridge), and leave the original physical table names as-is. Some organizations alias all physical tables to enforce best practice naming conventions. In this case, all mappings and joins are based on the alias tables rather than the original tables.
Now for creating joins you can make use of expression builder to have Primary Key and Foreign Key Relationships OR you can also have Complex Joins here over nonforeign key and primary key columns. When you create a complex join in the Physical layer, you specify the expression for the join. Like
Employee.employeeID=Fact.EmployeeId
and Dim table.deptname <> 'ABC'
You, can also have case statements here...
Hope this clears your funda regarding Alias Tables & Joins. Expression Builder is just the utility for developers to select the table, columns, expressions, variables and may other functions available.

If i use view in physical layer will it causes to performence

hi all
if i create a view in the physical layer will it causes to performance issue
can any one suggest me on it,bez i have to create 3 views
thanks

Hi,
Using Aliases is a better way to increase performace. You can refer the Vanilla RPD. Aliases are extensively used ther.
Thanks,
Imtiaz.

Unable to view data in Physical layer of RPD

I have OBIEE installed on my local machine using Oracle 10g as the database installed on a remote machine. I am able to create the DSN and test the connection pool on my local machine.
The Call interface is OCI 10g in the connection pool. I am able to import tables into the database in the Physical layer of the repository but when I try to VIEW Data in the physical layer, it throws me an error stating,
ORA-12514: TNS:listener does not currently know of service requested in connect descriptor at OCI call OCILogon.
nQsError: 17014 Could not connect to Oracle Database.
I have oracle 10g client installed on my local machine. I am able to view the tables and the data from SQL PLus. In OBIEE i am able to import tables but cannot view data.
Any suggestions on what could be causing this?

Sounds like one of my common issues. After you do the import, go back and check the connection pool. What I typically run into is that it has switched to the OCI connection rather than the ODBC connection used for the import, but it is still using the name of the ODBC DSN that was used for the import. Change it to the TNS name or the host:port/service and try again.
Rgds/Mark M

How to define join in physical layer between cube and relational table

Hi
I have a aggregated data in essbase cube. I want to supplement the information in the cube with data from relational source.
I read article http://community.altiusconsulting.com/blogs/altiustechblog/archive/2008/10/24/are-essbase-and-oracle-bi-enterprise-edition-obiee-a-match-made-in-heaven.aspx which describes how to do it.
From this article I gather that I have to define a complex join between the cube imported from essbase to my relational table in physical layer.
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In My case I am trying to join risk dimension in the cube based on risk_type_code (Gen3 member) with risk_type_code in relation table dt_risk_type.
How can I create this join?
Regards
Dhwaj

Hi
This has worked the BI server has joined the member from the oracle database to cube. So Now for risk type id defined in the cube I can view the risk type code and risk type name from the relational db.
But now if I want to find aggregated risk amount against a risk type id it brings back nothing. If I remove the join in the logical model then I get correct values. Is there a way by which I can combine phsical cube with relational model and still get the aggregated values in the cube?
I have changed the column risk amount to be sum in place of aggr_external both in logical and phsical model.
Regards,
Dhwaj

Issue while writing a query in table type select.in the physical layer

Hi gurus,
I am actually trying to create a table using select in the physical layer..... i acutally am not aware what it is called but its when i click a table in the physical layer i have an option table type and i chose select which allows me type my query..the query is
Select
coln name(which is a lengthly list of conversion) AS column_name
From Table name.
when i view the data rom the physical layer everthing seems to be fine. but when i try to view the data in the frnt end it gives me an error maximum length is too long than 128....
i am aware of this issue the sql server allows only column of length 128..but none of my column length is greater than 128..
Could you please help me in this
Many thanks in advance

hi veeravalli ,
Thanks for the reply....actually the corresponding reports for this have already been prepared...i created a view in the backend with the same select which i wrote before and and tried calling the view from her.. i have viewed the data and all is perfect...but when i try viewing it from the front end it error saying invaild object name select * from databasename.dbo.View_name...but i have checked the view exists in the backend...
Thanks in advance....

Creating views in Physical Layer of OBIEE Administration Tool

Hello,
I am doing a proof of concept of creating an OBIEE repository using the Administration Tool to make a model for an in house sandbox OLTP system. Because this POC isn't using a warehouse that is built nicely with everything I need, I am having to import the OLTP tables into the Physical Layer and then create a few extra views (by creating a new physical table object and selecting "Table Type: Select") to add some new columns I will need.
My problem is that once I have created two views 'ViewA' and 'ViewB', I want to then create a third view 'ViewC' that is the union of 'ViewA' and 'ViewB'. But when I create ViewC from these two views and try to then update row count or view data in newly created ViewC, I get an error message of the effect:
Message 208: Invalid object name 'DBO.ViewA'
Message 208: Invalid object name 'DBO.ViewB'
When I try and create ViewC with DBO.OriginalTableA and DBO.OriginalTableB, however, it works just fine. And I am also able to successfully update row count and view data in ViewA and ViewB independently. So it seems to me like a view initialization problem when trying to have ViewC be created from A and B.
Am I trying to do something that is not allowed in the Physical Layer of the BI Admin Tool? I would think that I should be able to work with views just like actual physical tables from my OLTP. Maybe not.
Any help or insight would be greatly appreciated. Many thanks.

Hi Hammett81 ,
I think, I have given configured connection pool correct. (following Oracle guidelines: 'In the Connection Pool dialog box, on the General tab, verify that the call interface is set to Default (OCI 10g) and change the data source name to the appropriate tnsnames.ora entry ( ORCL in this example). Please note that this is the TNS service name, not the ODBC DSN. ' )
I tried to give ODBC DSN (SH) as call interface, which resulted in an Error dialogue, implying, previous configuration was correct.
So, I reverted back.
Regards,
Deeba

Not able to update row count in Physical Layer..connection failed in OBIEE 11g

Hi Guys,
I am not able to do Update Row count in the Physical Layer, i am getting an error The Connection has failed. This is in OBIEE 11g Linux env.
I have put the tnsnames.ora file in the below path:
/*****/pkgs/linux/intel/OBIEE_DIT/MW_HOME/Oracle_BI1/network/admin/
I do not have admin under
/****/pkgs/linux/intel/OBIEE_DIT/MW_HOME/oracle_common/network/
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(DESCRIPTION =(ADDRESS = (PROTOCOL= TCP) (HOST= xxx.xxx.com) (PORT= 1671))(CONNECT_DATA = (SERVICE_NAME = US1OBIEE)))
I am not able to understand the issue..
Thanks,
Amit

Looks like rpd is looking for local tns config... try to use as hostname:port/ServiceName
This should work, just in case not working! stop doing so since it is know issue.
If helps mark

How to use BETWEEN Operator in physical layer in OBIEE 11g

Hi Experts,
How do I do the BETWEEN Operator functionality in Physical layer if my requirements is like this?
TABLE_1.COLUMN_1 = TABLE_2 is between COLUMN_2 and COLUMN_3
Below is the syntax for BETWEEN Operator function when I am trying to insert them.
<<expression>> BETWEEN <<Upper Bound>> AND <<Lower Bound>>
Thanks,
Edited by: OBIEE/BIP Forumer on Nov 3, 2012 11:37 PM

Below is an example diagram, as you can see, FACT TABLE have a join (an arrow one) towards TABLE_1 and TABLE_3. AS for the TABLE_3, this table is the one which I implement with the BETWEEN Operators function in Physical Layer. Also, the arrow in FACT TABLE and TABLE_3 is a red one with no arrow head line.
TABLE_2
^
l
l
l
FACT TABLE ---------> TABLE_1
l
l
l
TABLE_3
Edited by: OBIEE/BIP Forumer on Nov 4, 2012 2:33 AM

How to add a stand alone table from Physical layer to Business Model

Hi,
I have tables from 2 different database sources in my Physical Layer.
My Business model currently uses only tables from one database. from my second database in teh physical layer I need only one table and that will be a stand alone table, to my Presentation layer.
1. Does it have to go through my Business layer or can it be directly added to the Presentation layer. What are the steps?
2. Can I restrict the permissions on that stand alone table only to the administrator?
Thank you.

1)create a view with single column using the sql (select 1 from dual) in physical layer and join it with the table using complex join in physical layer (1=1).
Move that to BMM, set the column as key in both physical and bmm layer.
2) You can restrict the access for the table presentation layer
Double click the presentation layer table -> Permission -> there you can restrict the access by user or group
Thanks,
Vino

Creating filtered view on the physical layer ussing session variable USER

Hi:
I´m creating a view on the physical layer, the view needs to be created dynamically. So depending on the user (using the session variable USER) the view is created with the data a particular user is able to see.
Fisrt I imported the table and changed it´s properties to be created through a "Select Statement" so i don´t needed to change the mapping on the bussiness model layer.
The consistency check was OK but i´m not able to see data in answers, even using the Administrator user. Have anyone tried to do this? Here is my query.
Thanks
A Garcia
Select * from D_ESTRUCTURA_RH2 where Region_ID
IN
select distinct a.REGION_ID from APP_INDPERSONAL_DM.D_ESTRUCTURA_RH2 a
inner join (
select distinct b.REGION_ID from APP_INDPERSONAL_DM.D_ESTRUCTURA_RH2 b
where exists (select 1 from APP_INDPERSONAL_DM.Autorizacion a, usuarios c
where a.app_id = 1
and a.usuario_id = c.Usuario_Id
and UPPER(c.Nombre_Usuario)=UPPER(':USER')
and a.miembro_id = 'REGION_ID'
and a.operador = '='
and (b.REGION_ID = (case when valor = 'Todo' then 0 else valor end) or valor='Todo'))
) seguridad
on
a. REGION_ID = seguridad.REGION_ID
)

whay not use the same filter in the content tab of the logical table source?
check the physical sql sent to databse using web-admin-manage sessions-view log and see if there is any unexpected behavior. also run the same query in db and see iff you get the results in databse itself.

Physical Layer Joins

I am creating a data model from a database that is in 3rd Normal Form. My understanding in the physical layer I should make the joins based on the relation between tables. I have a CUSTOMER & ADDRESS table and I understand that my join will be 1:M here since 1 Customer can have many addresses. However I would like to get all my facts from the CUSTOMER table so since this is going to be the fact table should the Many end of the join be at the CUSTOMER table. I have been given much misinformation about this and have 2 scenarios but do not know which is correct.
Scenario #1: Model the joins in the physical layer as 1:M e.g 1 Customer has many Addresses and then reverse the joins in the BMM to make the CUSTOMER table a fact table.
Scenario #2: Model the joins in the physical layer making the M (Many) side of the join on the Customer table therefore choosing it as a fact table in the physical layer.
Thanks in advance for any answer.

So if I understand correctly then the join in the physical layer will look like this: CUSTOMER------------->ADDRESSES. Is this because the CUSTOMER table is going to be the fact table. I thought the relationship between Customer and Addresses is a 1:M i.e. 1 Customer has many addresses. Why do we not model this in the Physical Layer.

Aliases in physical layer

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