Peformance of report using report studio

[cognosbeginner]

Hello All

Does the number of data items in a query affect the performance of a report? I have multiple data items using dimensional functions. The complex data items are created kind of in a step-by-step manner using multiple data items, for ease of understanding. Although i do not have any issues with performance, i just want to know if there is any observation on this.

Thanks!

[gosoccer]

Are you dealing with cubes (OLAP)?

[cognosbeginner]

Yes, i'm building the report based on multiple cube datasources.

[gosoccer]

One of the biggest mistake I made was to perform string operations such as below. It slowed down the Reports big time.
Have the cube generation process to handle as much data conversion, calculations, etc. Pls see my mistake below,
case
when [dsCube].[SSS_TYP_CD - Long Name] = '01' then 'DD2S(ACT)'
when [dsCube].[SSS_TYP_CD - Long Name]= '02' then 'DD2(RES)'
:)