Regarding Line item dimensions

Hi all,
In our project for one of the cube 3 line item dimensions are maintained already , But still we have to create one more line item dimension for that infocube because the percentage for the one of the dimension and fact table is reached to 90%.So is it preferable to have more line item dimensions? If not please provide the alternative suggestion.
we maintained relative infoobects in dimensions.
Thanks & Regards,
Swarna.P

Hi,
If there is no other alternative to swap the Chars in between Dimensions, then go for Line Item Dimension. It won't be a problem if you have more then 2 or 3 Line Item Dimensions. I Used 4 Line Item Diemsions becasue the Ratio is crossing 90%. So Line Item is solution for my problem, first check the Chars in Dimensions and re-arrange it then check the Ratio, if it doesn't work then go for Line Item Dimension.
Thanks
Reddy

Similar Messages

Regarding line item dimension

Hi all,
what are the necessary prerequisities will u take regarding line item dimension.
for eg., for sd cubes we r using sales doc no., i.obj as a line item dimension? why can't the other i.obj?
plz explain me clearly?
Thanks & Regards,
V.Vijay.

HI,
Line Item and High Cardinality
When compared to a fact table, dimensions ideally have a small cardinality. However, there is an exception to this rule. For example, there are InfoCubes in which a characteristic document is used, in which case almost every entry in the fact table is assigned to a different document. This means that the dimension (or the associated dimension table) has almost as many entries as the fact table itself. We refer here to a degenerated dimension. In BW 2.0, this was also known as a line item dimension, in which case the characteristic responsible for the high cardinality was seen as a line item. Generally, relational and multi-dimensional database systems have problems to efficiently process such dimensions. You can use the indicators line item and high cardinality to execute the following optimizations:
Line Item Dimensions
Line item: This means the dimension contains precisely one characteristic. This means that the system does not create a dimension table. Instead, the SID table of the characteristic takes on the role of dimension table. Removing the dimension table has the following advantages:
¡ When loading transaction data, no IDs are generated for the entries in the dimension table. This number range operation can compromise performance precisely in the case where a degenerated dimension is involved.
¡ A table- having a very large cardinality- is removed from the star schema. As a result, the SQL-based queries are simpler. In many cases, the database optimizer can choose better execution plans.
Nevertheless, it also has a disadvantage: A dimension marked as a line item cannot subsequently include additional characteristics. This is only possible with normal dimensions.
High Cardinality
If your dim table size exceeds the 20% of your fact table then you can say it as high cardinality, for ex: your fact table contains 100 records and your customer dimension contains 25 records means this dim is with high cardinality. you can check with your client for the expected records for those dimensions or for the info objects which you define in one dimension. to know the sizes of the dimension tables and fact tables you can runa a program in SE37 SAP_INFOCUBE_DESIGNS, it displays all your info cubes fact and dimension tables with sizes, if any dimension exceeds the more than 10% to 20% it will be in RED.
It means that the dimension is to have a large number of instances (that is, a high cardinality). This information is used to carry out optimizations on a physical level in depending on the database platform. Different index types are used than is normally the case. A general rule is that a dimension has a high cardinality when the number of dimension entries is at least 20% of the fact table entries. If you are unsure, do not select a dimension having high cardinality.
http://help.sap.com/saphelp_nw04/helpdata/en/b2/fbb859c64611d295dd00a0c929b3c3/frameset.htm
http://help.sap.com/saphelp_nw70/helpdata/en/a7/d50f395fc8cb7fe10000000a11402f/frameset.htm
http://help.sap.com/saphelp_nw04/helpdata/en/5c/d14d3c306f090ae10000000a11405a/frameset.htm
Note: In SAP BW 3.0, the term line item dimension from SAP BW 2.0 must a) have precisely one characteristic and b) this characteristic must have a high cardinality. Before, the term line item dimension was often only associated with a). Hence the inclusion of this property in the above. Be aware that a line item dimension has a different meaning now than in SAP BW2.0.
SAP recommends that you use ODS objects, where possible, instead of InfoCubes for line items.
Tarak

Line Item dimension

Hi friends!
The auditor suggest us "flag the line item option in the dimensions with high cardinality, ie: document number, material number"
In my cubes have 0customer in dimension C toghether with other other characteristics, and 0material in dimension M together to other characteristics..
a) is the auditor suggest ok?
b) do I need mark this dimension as 'line item' in my cubes if the dimension M or C has more than one char?
c) do I need change the arquitecture in my cube and leave 0material alone in dimension M and in dim C only the char 0customer?
Thanks in advance!

Regarding High Cardinality :
If the values in the table are distinct - where the uniqueness of the values is high - a Bitmap index is preferred since the unique values are high...
As for Line item dimension - in a Line Item dimension - only one characteristic is allowed in a line item dimension and the SIDs will get stored directly in the Fact Table and the additional lookup of SIDs with the master data is avoided...
a) is the auditor suggest ok?
I would say that high cardinality is a better option as opposed to line item dimension . For Document Number - a Line item Dimension is preferred since Document number is typically used in reporting but not much on searches for the same ..
Also this is with the information you have given - it could also be that there is some more information to it that Line Item Dimensions were suggested ...
b) do I need mark this dimension as 'line item' in my cubes if the dimension M or C has more than one char?
You can mark a dimension as Line Item only if there is one characteristic
c) do I need change the arquitecture in my cube and leave 0material alone in dimension M and in dim C only the char 0customer?
Keep document number in line item - run the report to analyze the sizes of fact versus dimensions and then rearrange the characteristics to get better ratios instead of making Material and Customer as Line item Dimensions...
Also Material and Customer are usually viewed along with their Nav Attribtes - making them as Line Item will not give you much savings in terms of performance
Edited by: Arun Varadarajan on Mar 25, 2010 1:13 AM

What is line item dimension and cardinality in BI 7.0

Can u plz suggest me what is line item dimension and cardinality in BI 7.0..
Thanks in advance.
Venkat

Hi Babu
Line item: This means the dimension contains precisely one characteristic. This means that the system does not create a dimension table. Instead, the SID table of the characteristic takes on the role of dimension table. Removing the dimension table has the following advantages:
¡ When loading transaction data, no IDs are generated for the entries in the dimension table. This number range operation can compromise performance precisely in the case where a degenerated dimension is involved.
¡ A table- having a very large cardinality- is removed from the star schema. As a result, the SQL-based queries are simpler. In many cases, the database optimizer can choose better execution plans.
Nevertheless, it also has a disadvantage: A dimension marked as a line item cannot subsequently include additional characteristics. This is only possible with normal dimensions.
Note: In SAP BW 3.0, the term line item dimension from SAP BW 2.0 must a) have precisely one characteristic and b) this characteristic must have a high cardinality. Before, the term line item dimension was often only associated with a). Hence the inclusion of this property in the above. Be aware that a line item dimension has a different meaning now than in SAP BW2.0.
SAP recommends that you use ODS objects, where possible, instead of InfoCubes for line items.
Hope this helps.
Plz check these links:
SAP Help:
http://help.sap.com/saphelp_nw04s/helpdata/en/a7/d50f395fc8cb7fe10000000a11402f/frameset.htm
Thanks & Regards
Reward if helped
Edited by: Noor Ahmed khan on Aug 5, 2008 2:36 PM

Line item dimensions

hi..
wat is line item dimensions nd cardinal heights???
regards
deepa

Hi Deepa,
Line Item Dimension:
When your dimension table becomes large (>10% of the fact table) then you can make the dimension a "line-item" dimension. The constraint is that the dimension should have only 1 characteristic. By making the dimension as line item the SID values are directly used instead of the Dim ids and the query performance is better.
The disadvantage is that once you make the dimension line -item you cannot add another characteristic to that dimension and you cannot remove the line -item checkmark without deleting the cube data.
http://help.sap.com/saphelp_nw04/helpdata/en/a7/d50f395fc8cb7fe10000000a11402f/frameset.htm
Multi Dimensional modelling will include fact table in center with Dimension tables around it. Overall system performance is greatly affected and dependent on the size of these dimension tables in respect to the fact table. SAP recommends that size of dimension table should be 20% of the size of fact table. In case if this size is more than 40% dimension should be defined high cardinal ( should be supported by database) If dimension tables are more than 40% the dimension should be defined as line item. When dimension is defined as line item, Dim ID in the fact table is replaced with the SID ID, Only one characteristic will be defined in that dimension. This results in improved performace.
Here is how it will work
Fact table
Dim ID1 DIM ID2 DIM ID3 AMOUNT QTY
Dimension Table 1
Sid1 DimID1
Dimension Table 2
Sid 4 Dim ID 2
Dimension Table 3
Sid6 Dim ID 3
Cosidering that Dim1 is too big, We can define Sid 1 in Line Item Dimension and Dim ID 1 is replaced by Sid 1 so fact table will look like this
Sid 1 Dim2 Dim3 Amount Qty
Compounding Attribute is superior object to define characteristic, for example
Plant A manufactures TV
Plant B manufacture TV
The only way to differentiate product can be TV and Plant A
Also,
Cost center 100 can be in Controlling Area A and
Controlling Area B can also have cost center 200,
So Cost center is compounded with CO Area to uniquely identify that line.
Just check this thread line item dimension
Cardinality defines the numeric relationships between occurrences of the entities on either end of the relationship line.
Check this link:
http://www.datamodel.org/DataModelCardinality.html
For cubes -> High Cardinality means that this dimension contains a large number of characteristic values. This information is used in accordance with the individual database platform in order to optimize performance. For example, an index type other than the standard may be used. Generally a dimension is perceived to have high cardinality when the dimension is at least 20% the size of the fact tables in terms of the number of entries each contain. Avoid marking a dimension as having high cardinality if you are in any doubt.
Also refer the below link for Line Item Dim and High Cardinality.
http://help.sap.com/saphelp_nw04/helpdata/en/a7/d50f395fc8cb7fe10000000a11402f/frameset.htm
Check this explanation by pizzman:
Re: High cardinality (CARDHeight) vs Line item
Refer these links on line-item and cardinality:
Line Item Dimension
Re: Line Item Dimension
Cardinality
Re: High Cardinality Flag
****Assign Points If Helpful****
Regards,
Ravikanth

How to know what were line item dimensions

Dear SDN,
How to know what were made line item dimensions.
Thankyou.

Rahul,
Go to the edit mode of your info cube and then check out your dimensions, there if the line item dimension check box is checked then it means that, that particular dimension is a Line item dimension.
Regards,
Gattu

Usage of line item dimension - design or run time?

Hi,
Can anyone please tell me at which stage a line item dimension is considered - at design time or after data load, once queries are run and performance degenerates?
I have read many posts and blogs about line item dimension and high cardinality, but I would require more information on when a line item dimension comes into play.
If we can decide at design time, then how is it done without data being loaded?
At which instances will the dimension table size exceed the fact table's size?
Please explain the above 2 points with a clear example, including the DIM ID and SID table access, and the ratio calculation for line item dimension consideration.
Thanks in advance.

Hello Aparajitha,
I agree with Suhas on point of consideration of LID . It would be good enough to consider a Dimension as LID in the Cube during design, it will be fruitful for the performance point of view. There is no point in saving the LID for future purpose if you have less than 13 Dimension in the Cube. It is going to save a extra join in connecting the relevant data.
If the total Dimension exceeds 13 or more (during design) , then you no option but include the related Char IO together in a one dimension.Here you cannot make a LID .
During the run phase, if the Dim table is more than 20 % of Fact Table, then for the sake of performance you have to go for the LID.In that case you will have the overhead of managing data (backup, delete & restore) .
On your specific questions :
"If we can decide at design time, then how is it done without data being loaded "
Technically same as you do during run-- Goto Dimension -- Right click --Properties -- and Check LID.
Logically -- Depending upon the Business meaning, which char has max unique values you can go with as LID.
"At which instances will the dimension table size exceed the fact table's size "
Frankly I haven't come across that.. ... Fact table is the center table and always will be the huge table in comparison to Dim table . Dim table cannot exceed the Fact Table ....!
Yes if the size of Dim Table is more than 20% of Fact table ( ratio of Dim Table to Fact Table) , then we have to select between the LID or High Cardanility.
Gurus..Please correct if anything is wrong ..!
Regards
YN

The impact to use line item dimension

Hi,guys,
I have a question here:
When modeling a cube,we can use the line item dimesion to improve the reading performance in some cases.for example when we use SD doc. characteristic as a line item dimesion.
But what I wonder is there any limitation or impact when we use this function? What about if I click this function even for a casual characteristic like bussiness area or something? Is that useful to improve performance or impact vice versa?
Hope someone could help me.
Thanks

Hello Johnson,
The Infocube has extended star shema structure, i.e fact table contains Key figures & Dimentions, so characteristics is link with SID (Surrogate ID) to dimention table for faster access the data. These SID is further link with ur Master Data.
In this case dimension tables are eliminated and characteristics infoobjects SID is directly written in the fact table insted of dimension id so it will improve the performance.
SAP recommends that you use ODS objects, where possible, instead of InfoCubes for line items
If you are looking at better query performance and you have less than 13 chars. in ur datamodel, then you can place them individually in each dimension. make the dimensions as line item Dim .
In this case Line item IC is better than ODS.
but if you are having many data fields and you want to report on lowest granularity of data, then ODS is better option.
For Example :
Line item dimension for Order or Order item contains huge data, same as fact table. two huge table joins creates performance issues.
So SAP suggests, ODS reporting is good for Order level reporting then Line item dimensions.
Advantages of Line item :
Line item dimension is used to improve queryperformance.
Instead of joining fact table to dimension reduce joints
Disadvantages of line item :
A dimension marked as a line item cannot subsequently include additional characteristics.
Hope it clears ur doubt,
Regards,
Santosh

How Line Item Dimensions

Hi..
I found some dimensions need to be conveted into line items. but when checked with cube that dimension has more than 1 characteristics. In that case what i have to do..and how can i convert it into line items

Hi Rajini...
1. When you anticipate high growth in the dimension tables of an entity.
2. Usually you decide whether a char is to in a line item dimension or not.
3. SAP recommends to have ODS for line items rather than cube; cube should have summarised data.
Also, see this link:
http://help.sap.com/saphelp_nw70/helpdata/en/a7/d50f395fc8cb7fe10000000a11402f/frameset.htm
Using Line Item Dimension
remodeling :
http://help.sap.com/saphelp_nw70/helpdata/en/58/85e5414f070640e10000000a1550b0/content.htm
regards,
supriya

Regarding line-item-dimention

hi,
plz clarify my doubt regarding line-item-dimention.
When line-item Dimensions are used without containing the line-item characteristic in the aggregate, which aggregate should be built?
thanks,
Neelima.

Hi Nl .G
Aggregates can be built out of other aggregates to reduce the amount of data to be read and, hence, to improve the roll-up performance Aggregate hierarchy is determined automatically.
In order to use an aggregate in the first place, it must be defined activated and filled. When you activate it, the required tables are created in the database from the aggregate definition. Technically speaking, an aggregate is actually a separate BasicCube with its own fact table and dimension tables. Dimension tables that agree with the InfoCube are used together. Upon creation, every aggregate is given a six-digit number that starts with the figure1.
am sure using basic aggreate will solve this issue..Try and let me know..
any furthur info you can read from the given link..
[Aggregates|https://www.sdn.sap.com/irj/servlet/prt/portal/prtroot/docs/library/uuid/cbd2d390-0201-0010-8eab-a8a9269a23c2]
Edited by: Prasanna Kumar Perla on Aug 4, 2008 1:52 PM

Line item dimensions and cardinality?

hi all,
how to identify nor use the cardinality relationship as well as the line item dimension?
can anyone explain me about it. since i am trying to create an multi provider which enables to fetch data from 3 ods.
regds
Hari Chintu

Hi,
Below is some useful information on Line item dimension and high cardinality.
These concepts hold good for Cube design only, coming to ODS, these dont help you. As ODS is nothin but a flat structure, we do not have the facility of Star schema. Reporting on ODS can lead to performance issues, it is better to load data from ODS into Cube and then have a multiprovider on them instead of having it on ODS.
Hope this helps.
Regards,
Kalyan
Use
When compared to a fact table, dimensions ideally have a small cardinality. However, there is an exception to this rule. For example, there are InfoCubes in which a characteristic document is used, in which case almost every entry in the fact table is assigned to a different document. This means that the dimension (or the associated dimension table) has almost as many entries as the fact table itself. We refer here to a degenerated dimension. In BW 2.0, this was also known as a line item dimension, in which case the characteristic responsible for the high cardinality was seen as a line item. Generally, relational and multi-dimensional database systems have problems to efficiently process such dimensions. You can use the indicators line item and high cardinality to execute the following optimizations:
       1.      Line item: This means the dimension contains precisely one characteristic. This means that the system does not create a dimension table. Instead, the SID table of the characteristic takes on the role of dimension table. Removing the dimension table has the following advantages:
        When loading transaction data, no IDs are generated for the entries in the dimension table. This number range operation can compromise performance precisely in the case where a degenerated dimension is involved.
        A table- having a very large cardinality- is removed from the star schema. As a result, the SQL-based queries are simpler. In many cases, the database optimizer can choose better execution plans.
Nevertheless, it also has a disadvantage: A dimension marked as a line item cannot subsequently include additional characteristics. This is only possible with normal dimensions.
       2.      High cardinality: This means that the dimension is to have a large number of instances (that is, a high cardinality). This information is used to carry out optimizations on a physical level in depending on the database platform. Different index types are used than is normally the case. A general rule is that a dimension has a high cardinality when the number of dimension entries is at least 20% of the fact table entries. If you are unsure, do not select a dimension having high cardinality.
Note: In SAP BW 3.0, the term line item dimension from SAP BW 2.0 must a) have precisely one characteristic and b) this characteristic must have a high cardinality. Before, the term line item dimension was often only associated with a). Hence the inclusion of this property in the above. Be aware that a line item dimension has a different meaning now than in SAP BW2.0.
However, we recommend that you use ODS objects, where possible, instead of InfoCubes for line items. See Creating ODS Objects.
Activities
When creating dimensions in the InfoCube maintenance, flag the relevant dimension as a Line Item/ having High Cardinality.

Line Item Dimension and Navigational attribute

Hi Gurus,
Can somebody tell me how line item Dimensions and navigational attributes works technically?
What are the pros and cons for them?
Regards
Alex

Hi Alex,
You will use navigational attributes based on how you want to track and report history. Let me explain with an example.
Customer Bubba is assigned Sales Group XYZ in Jan 2007. In July the Sales Group on the Customer Master record is changed to ABC. Your are looking at the sales report.
1). If you want to see all the sales made to Customer Bubba at the time of reporting (current) then you will use navigational attributes You will create 0SALESGRP as the navigational attribute of 0CUSTOMER . Then all sales to the customer will show up under Sales Group ABC.
2). If you want to see all the sales made to the customer at the time the actual transaction occured then you will add Sales Group as a characteristic of the InfoCube. Then sales from Jan - June 2007 will show under Sales Group XYZ and from July - Present will show under Sales Group ABC.
Performance issue occurs because navigational attribute is stored outside of the dimension table of the cube and is stored in separate master data tables. So query has to perform additional table read. So essentially there are advantages and disadvantages of usng navigational attributes. It is business requirement that will drive the use of navigational attribute.
Hope this helps!!!. Please assign points.

Converting Line item dimension to non line item dimension

I have some BI 7.0 issues.
For some of the existing cubes I had certain dimension as line item dimension - I wanted to add some characteristic to these dimensions. I am able to do this change and activate the cube.
But we noticed that the data which is a part of the line item dimension is lost. If the data set is small then we could have done a reload but in my case the volumes are huge, so reloading data is not a possible solution. We actually did the same exercise in BW 3.5 and noticed that the data is intact. We have looked into OSS notes and not found anything so far.
Kindly help me to find a way to convert Line item dimension to non line item dimension in BI 7.0 without loosing Data.

Hi,
the only way to do is to generate a new cube and transfer the data from the first cube via transformation rule. A conversion within the existing cube is not possible.
Regards,
C. Aslan.

BW : Line Item Dimension

Hii All,
Can you plz explain what is Line Item Dimensions...with examples.I am confused.
Plz help.
Thanks & Regards,
Madhavi S Bichakal

Hi
Line Item and High Cardinality
Use
When compared to a fact table, dimensions ideally have a small cardinality. However, there is an exception to this rule. For example, there are InfoCubes in which a characteristic document is used, in which case almost every entry in the fact table is assigned to a different document. This means that the dimension (or the associated dimension table) has almost as many entries as the fact table itself. We refer here to a degenerated dimension. In BW 2.0, this was also known as a line item dimension, in which case the characteristic responsible for the high cardinality was seen as a line item. Generally, relational and multi-dimensional database systems have problems to efficiently process such dimensions. You can use the indicators line item and high cardinality to execute the following optimizations:
       1.      Line item: This means the dimension contains precisely one characteristic. This means that the system does not create a dimension table. Instead, the SID table of the characteristic takes on the role of dimension table. Removing the dimension table has the following advantages:
¡        When loading transaction data, no IDs are generated for the entries in the dimension table. This number range operation can compromise performance precisely in the case where a degenerated dimension is involved.
¡        A table- having a very large cardinality- is removed from the star schema. As a result, the SQL-based queries are simpler. In many cases, the database optimizer can choose better execution plans.
Nevertheless, it also has a disadvantage: A dimension marked as a line item cannot subsequently include additional characteristics. This is only possible with normal dimensions.
       2.      High cardinality: This means that the dimension is to have a large number of instances (that is, a high cardinality). This information is used to carry out optimizations on a physical level in depending on the database platform. Different index types are used than is normally the case. A general rule is that a dimension has a high cardinality when the number of dimension entries is at least 20% of the fact table entries. If you are unsure, do not select a dimension having high cardinality.
Note: In SAP BW 3.0, the term line item dimension from SAP BW 2.0 must a) have precisely one characteristic and b) this characteristic must have a high cardinality. Before, the term line item dimension was often only associated with a). Hence the inclusion of this property in the above. Be aware that a line item dimension has a different meaning now than in SAP BW2.0.

Infocube line item dimension and performance optimization

Hi,
I remodelled an infocube and line item dimension contains only one characteristics set as line item dimension.
previously the dimension as one characteristics but it wasn't set as line item dimension.
and when I checked the SAP_INFOCUBE_DESIGNS from SE38 it looks ok.
/SAP/CUBE /SAP/CUBE3 rows: 8663 ratio: 3 %
After setting it as line item the rows is now minus but it is showing red which means that there is problem with the dimension
/SAP/CUBE /SAP/CUBE3 rows: 1- ratio: 0 %
Its this a performance problem since it is showing red.
thanks

hi,
No,its not performance issue.
for a dimension to be line item dimension...the dimension size shouldn't be more than 20% size of the fact table size.
when a dimension is set as line item dimension,the regarding SID will be placed in Fact Table,but not the DIM ID.
may be that is the reason when your dimension is not line item dimension,it shows the number of rows and when it is made line item dimension,its not showing any rows and the ratio also null.
hope this is clear for you.
Regards
Ramsunder

Regarding Line item dimensions

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