Use of Line Item

[Former Member]

Hi

Is there any effect of dimensions which more than 20% of fact table in upload performance. if yes. how it will effect the performance.

[Former Member]

Hello Rajini

I guess you are not asking for line item dimension...ur question is simple that if dim size exceed 20%

I dont think uploading will be affected as for every records KF has to be assigned to a set of DIM ID and they are created as per the master data combination...but yes it is going to hamper your data retrieval performance in reporting and that is our main concern...

When you retrieve data you go by master data then SID then DIM ID and then reach to Fact table to get KF. If your DIM table size is large then to search DIM ID for SID combination in a large table will consume lot of time...

So its always advisable to keep Dimension table size less then 20%...Now why 20% why not 10% -> Basically there is a trade off between dimension size and max no. of dimension u can use...if you reduce the no. of dimension in a cube then dimension size will be very large and surely may exceed 20% limit and if you reduce your limit then no. of dimension will be higher ( So many joints will reduce performance) so SAP has come up with this combination to get data faster and efficient way.

If you create it as a line item then definitely it will improve loading and reporting performance because no DIM ID is required...

Thanks

Tripple k

Message was edited by:

Tripple k

[Former Member]

Hi

As per my kowledge It will affect the loading performance as well because if there is no DIM table then there is no need of creating DIM Ids for that particular char...Dim Ids will be generated after loading the Transaction data...

Correct me if i am wrong....

Thanks

Khaja

[Former Member]

Hi

It will affect reporting performance not upload performance...While reporting if you have very long table, the data needs to be fetched from this table though you do not require all the data in the table, the system needs to refer the respective SIDs and DIM ids to arrived at the results set you request.

Regards

N Ganesh

[Former Member]

HI

Line item dimension 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.

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.

But the disadvantage is a line item dimesnion cannot subsequently include additional characteristics. This is only possible with normal dimensions.

Thanks

Khaja