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.
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Marc Reed
Reporting Lead
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Original Message:
Sent: Wed July 09, 2025 06:23 AM
From: Mack L
Subject: Report in Cognos performing poorly due to a Repeater table
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,
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Mack L
Original Message:
Sent: Thu July 03, 2025 08:03 AM
From: Patrick Neveu
Subject: Report in Cognos performing poorly due to a Repeater table
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,
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Patrick Neveu
BSL Consulting
IBM Champion
Original Message:
Sent: Wed July 02, 2025 07:27 AM
From: Mack L
Subject: Report in Cognos performing poorly due to a Repeater table
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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