Affect of using Line Item Dimensions

Hi Guys!!
My Cube model involves 4 line item dimensions.
I wanted to know if this will have any affect on the performance during loading/reporting on the cube.
Marking as a line item would cut down on one join during reporting. Please do let me know ur views on this!
Thanks,
Dennis.

Hi,
Line item dimension is one way good for reporting. The impact on loading needs to be considererd keeping in view the volume of records for each load.
Also SAP recommends to use ODS objects, where possible instead of cubes for line items."High Cardinality" is used to adjust indexing for a dimension. Whichmeans there may be some performance impact I believe.
Hope this helps you.....
Message was edited by: AVR - IGA

Similar Messages

Using Line Item Dimension

Hello Gurus
We have finished all initial loads to BW and now we are facing problems during the segmentation in CRM, using queries from BW.
SAP consultants indicated to use Line Item dimension.
Can we do it now? It is possible now to flag line item after the initial load?
We made the aggregation/compression and our problem still the same.
Thanks a lot!
Cristina Barbosa

Dear Bhanu Gupta,
I´m CRM consultant and I´m not a BW expert, but I need to finish this project.
I read about Line item and my quastion is:
You wrote me we cannot use line item now.
Can we insert severeal characteristics in normal dimension?
It will be helpful? In other words, this can increase the performance as line item?
We can´t delete the data in the cube.
In one of this cube, we have more than 40 millions facts.
Is there something else we can to to improve the performance?
Thanks for your help and patience.
Cristina

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

Re: Line Item Dimension

Hi everyone,
Can anyone please give me a real time scenario to use line item dimension. i mean when to use it and why to use it using a real time example like document number or invoice number.
thank you,
chintan

This topic comes up regularly. Seach the BI forums on "Line Item Dimension" and you'll find several threads that go into detail.
Searching the forums first is a great way to learn about a topic, then come back and post questions where you need more detail, or didn't quite understand something.
Put yourself on the SDN world map (http://sdn.idizaai.be/sdn_world/sdn_world.html) and earn 25 points.
Spread the wor(l)d!
Pizzaman

InfoCube Design for Variable data - Use of Line Item Dimensions

I have an infoprovider based on billing conditions which we have extended the extractor structure for 2LIS13_VDKON and we now have a requirement to add Customer fields such as Customer Purchase Order Number and Contract Number. These fields are obviously highly variable. I have added to them to the reporting DSO and now need advice on what is the best way to add these types of fields as reportable dimensions to the infocube so as to not impact performance? I currently have 9 dimensions with multiple charachteristics and a time dimension. Should I just create a line item dimension for Purchase Order? Problem is I have 8 other line item dimensions to add which are customer specific reporting fields that we capture on the sales order and wish to report on. I know there is a limit of 16 dimensions and I am also concerned about performance.
Any advice is greatly appreciated
Lee Lewis

Hi,
To make sure that the infocube you have created should not have any performance issue: Please do the following
Go to RSRV > All elementary tests-> Database---> database information about infoprovider tables
Upon clicking on database information about infoprovider tables, on the right hand side, in the parameter enter your infocube name and execute and see the log: ( log will automatically popping up once you are done with execution )
There see the database infomation about infoprovider:
This log wil make you to understand how well you have designed your infocube and make sure that each (f ) table corresponding to each dimension will not exceed 20 % of the infocube size.
You create dimensions of infocubes in a such a way ( whether line item or normal dimension ) so that any of the dimensional F table will not exceed 20 % of the infocube size.
Actually this will give us the information of the size of the data of particular dimension and there by if any particular dimension is exceeding the 20 % of the infocube size, then you need to create line item dimension for the characteristics existing in that dimension .
After creating again, test it and see whether any of the dimension table exceeding 20% infocube size .
Repeat this process until you see all dim F tables less than 20 % of the info cube table size
This will negate any performance issues arise in reporting
Edited by: S Simran on Nov 6, 2009 10:11 AM

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

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 dimension wont insert sid values in infoobject sid table

Hi all,
I have a strange problem, whenever I load data into a cube which has a line item dimension on 0customer without first loading the master data I am getting inconsistency in RSRV saying that no corresponding DIMid exists in sid table.
So there are Dimids in the fact table but the dimension table, which is same as the sid table in the the case of line item dimension, doesnt have them.
Can someone explain me why is this happening? I thought if a characteristic value doesnt exist in the master data but comes in through the transaction data it inserts the same in the sid table.
Is there a different rule for line item dimensions? Can someone point me to some OSS or documentation?
thanks

Thanks all..
To clear up a few questions:
1. What I mean by <i>"So there are Dimids in the fact table but the dimension table, which is same as the sid table in the the case of line item dimension, doesnt have them"</i> is:
the line item dimension table /bic/D<cubename>9 which is really a view on the sid table for characteristic /bic/s<ch. name> does have all the sid values (or all the dim values) as the fact table.
So fact table has more entries for that dimension than the sid table.
2. Yes we are facing reporting errors where we cannot drill down by that infoobject and LISTCUBE doesnt show us any cube data when that characteristic is chosen for display.
3. I have checked notes where it seems to be a RSRV bug but in our case it doesnt seem to be as observed in the actual table mentioned in #1
Now it is apparent that I am right both from help.sap.com link and what I am observing that for line item dimensions master data HAS TO BE LOADED FIRST for the characteristics used as a line item.

DB Statistics on Line item dimension

Hello,
We have a new cube with WBS element as line item dimension. the cube has around 600,000 records in fact table. The problem is the DB statistics is stuck at sampling the master data table for WBS element.
In all our cubes WBS element is always a line item and we do stats for these cubes every week, so why is this taking long. I thought that stats is per table and not per infocube? Correct me if I am wrong.
I would also like to if performing stats from the backend like DB13 jobs or DB20 or ORACLE DB is better and sufficient or the Cube Stats is also needed.
Thanks

Just saw this - in 3.1 SP22 - OSS Note <a href="https://websmp201.sap-ag.de/~form/sapnet?_FRAME=CONTAINER&_OBJECT=012003146900000348972005">862176</a> indicates that statistics collection on all dependent tables for a cube from the performance tab or as a result of automation settings should <b>NOT</b> be ocurring - just collection on F fact and dimension tables.
This note provides a fix. This should speed up statistics collection if you use these methods.

Line Item Dimension in a Infocube

Hi,
What is a Line Item Dimension in BI and
How can/based on What factors we can decide declare a Infoobject as a Line Item dimension in Cube
How to measure size of the fact table
Thanks

Hi,
For working out the largest fact tables:
transaction DB02 -> space statistics -> top n largest tables.
If this does not help, your DB administrator should be able to extract the information using SQL.
Also you can use tcode ST14 -> BW Evaluation: performance analysis of BW objects.
Rgds,
Colum

Line item dimension issue

Hi,
      I am on development system and want to know the fact and dimension % as I need to create line item dimesion.
One solution is executing program SAP_INFOCUBE_DESIGN.
      But if I want to use this same program in Production system, it will take a lot of time and will engage resources......
      Kindly suggest me as to how to find out which dimension should be made a line item dimension?
Thanks,
Sonu

Hi,
Use RSRV.
Execute RSTRV and here you have the option of single cubes.
This takes the ourput from the same tables where the SAP_INFOCUBE_DESIGNS takes.
All Elementary Tests -> Database -> Database Information about InfoProvider Tables.
Give your infocube name here and execute.
It gives you a good detailed output.
Thanks
Ajeet

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

Table for line item dimensions

Hello SDN,
Any table gives info about what all line item dimensions are used in Cubes.
Goodday.

hi,
there is no table which contains info. about what are the line item dimensuins in a cube.
use LISTSCHEMA t-code to know the tables in a cube.
or got SE11, give Dim table name ie /BIC/D<cube name><dim no>
serach the keyfield.
or check directly in infocube edit.

Affect of using Line Item Dimensions

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