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  • 1.  Report in Cognos performing poorly due to a Repeater table

    Posted 28 days ago

    Hi,

    I am trying to improve the performance of a report that includes a repeater table which displays charts with settings 2 across and 21 down. The repeater table is slowing down the report to a great extent. Could you please suggest ways to improve the performance?. Would also like to know if I can use some thing else instead of the repeater table.

    Regards, 



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    Mack L
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  • 2.  RE: Report in Cognos performing poorly due to a Repeater table

    Posted 27 days ago

    Hi Mack,

    your first step should be to find out the bottleneck. Probably it's not the data base, but either the Cognos server or your local computer (and it's browser). If it's the Cognos server, caching or using data sets might help. If it's the browser taking much time rendering, you should opt for simplification. Strip your charts down to the minimum (no reference lines, no ticks and so on). 



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    Thomas Wolf
    BI Professional
    Techniker Krankenkasse
    Hamburg
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  • 3.  RE: Report in Cognos performing poorly due to a Repeater table

    Posted 27 days ago

    Hi Mack,

    Which version do you use?

    You might want to check Include performance details. From Report (in Edit mode), click on Run actions, then choose Show run options:

    In the Run options dialog box, enable Include performance details.


    When you run your report in HTML for instance, you will see:

    and

    It might help to understand where is the bottleneck: Query and/or Render.

    Best regards,



    ------------------------------
    Patrick Neveu
    BSL Consulting
    IBM Champion
    ------------------------------



  • 4.  RE: Report in Cognos performing poorly due to a Repeater table

    Posted 21 days ago

    Hi @Patrick Neveu,

    The used the above method - 'Include performance details' and based on the readings, found that the query that is repeatedly executed for the Repeater table is the issue and not the rendering of the charts. Each execution of the query (for a chart) is taking around 2 seconds where the number of charts displayed is 30 plus in the repeater table causing the report to take more than one minute to render. I am trying to replace the repeater table with a list with chart inserted in it using a master detail relationship.

    If you have any ideas to improve the performance of the query, please suggest. Thank you so much.

    Regards,



    ------------------------------
    Mack L
    ------------------------------



  • 5.  RE: Report in Cognos performing poorly due to a Repeater table

    Posted 21 days ago

    If you have 30 charts, then each chart will execute it's own query and run time.Replacing the chart container with a list won't reduce the fact you have 30 charts needing 30 queries.  30 charts, 2 seconds a query, results in 60 seconds.

    It doesn't matter if you have 30 charts in a list, repeater table, or anything else - still 30 * 2 seconds.  

    Have a look at https://community.ibm.com/community/user/blogs/marc-reed/2024/05/22/more-efficient-report-microcharts to see if the technique could help you.



    ------------------------------
    Marc Reed
    Reporting Lead
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  • 6.  RE: Report in Cognos performing poorly due to a Repeater table

    Posted 23 days ago

    Hi, 

    Repeater table may use Master-Detail relationship and because of it you are facing this issue with performance. Take a look at this and how relationship has been made.
    Another point is your underlying query has on items used in report? Because of mater-detail, report may query unnecessary items.



    ------------------------------
    Jeam Coelho
    Cognos Solution Architect

    IBM Champion

    LinkedIn: https://www.linkedin.com/in/jeamcoelho/
    ------------------------------



  • 7.  RE: Report in Cognos performing poorly due to a Repeater table

    Posted 22 days ago

    You think the issue is the repeater table.

    First thing I would do is remove all content from the repeater table cells, charts etc, and just leave in a single data item from the repeater table query and run that. Is that slow?
    I would compare the performance of the empty repeater table to a list based on the same query. How close are they in run times?

    If you have a lot of content within the repeater cells, then it is more likely those that are the reason for poor performance rather than the repeater.



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    Marc Reed
    Reporting Lead
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