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Thread: Report Performance is bad even when moving between report pages

  1. #1
    Join Date
    Feb 2012
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    7

    Default Report Performance is bad even when moving between report pages

    I have a report that will always contain a large number of rows, when deploying this report to BI server version 4.1, the report takes a long time to load and I understand that the whole report is being completely rendered, but moving to any other page in the report is still very slow and looking at the logs it seems that the report as re-rendered completely when moving from page to page, attached is the configurations im using, anyone has an idea about what is going on?

    Note: had to rename classic-engine.properties to classic-engine.xml
    Attached Files Attached Files

  2. #2
    Join Date
    Mar 2003
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    8,085

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    I assume you are talking about the BI-Server's report-viewer. Yes, the report-viewer is stateless and therefore re-renders the report from scratch each time.

    If your report has many pages, then there is not much you can do about it. You can try to enable report-caching by setting the master-report's 'report-cache' attribute. This should speed things a bit. The report cache holds on to the report by storing it into the session. The report will be held at the paginated state. However, the report also will continue to consume memory (as it is not closed yet) and will also keep all used database connection open.

    Make sure that your EHCache configuration can deal with that, and that you do not hold on to reports for to long. The cache that governs the report-caching is 'report-output-handlers'. If your system cannot hold 500 connections open, I would recommend that you reduce the number of elements in that cache.

    Depending on the size of the dataset - especially if you hold it in memory and there is no scrollable resultset backing it - each report can consume a considerable amount of memory, so if you run out of memory, decrease the amount of reports held in cache even further.

    Personally, I would start by setting the number of elements to 5 and if needed, go upwards from there.
    Get the latest news and tips and tricks for Pentaho Reporting at the Pentaho Reporting Blog.

  3. #3
    Join Date
    Feb 2012
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    7

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    In this case what are my options If I want it to display paginated large reports to users with acceptable performance while loading the report and moving between pages? how can this be done?

    Thanks a lot Taqua

  4. #4
    Join Date
    Mar 2003
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    Use PDF. That downloads the full report to the client and they can view it locally. If you are on Windows, then the PDF-plugin from Acrobat should even display it inline.

    However: A BI tool is only as good as its reports.

    No one I know would be willing to search through even a 100 page report to find nuggets of information. Oh, they will tell their boss they do it regularly, but heck they do.

    Use parametrization to deliver targeted information to your users. Most users only care about a summary and maybe some local information related to their job. Sales people for the US usually dont need sales data for Europe (except for inter-departmental competitions - so let them filter to the bits they need to get their job done.

    Why not change your long list report into a smaller summary report, where users can drill to a detailed report (via drill-linking) if necessary?

    Make that summary report smart - indicate critical changes (10% less sales than last moth) or critical states (we are over budget!) by using colors or other indicators. Use charts or spark-line graphs to get visual information into the report. People are bad at reading through lists, a good chart compresses 1000 lines of data into a single picture.


    In a good BI setup, huge reports only exist for archives. Banks need to print massive reports for regulators - see above on whether they are read - but they dont browse them interactively. They are just stored on disk or tape.
    Get the latest news and tips and tricks for Pentaho Reporting at the Pentaho Reporting Blog.

  5. #5
    Join Date
    Feb 2012
    Posts
    7

    Default

    Thanks for the great ideas!!!!!!!

    Quote Originally Posted by Taqua View Post
    Use PDF. That downloads the full report to the client and they can view it locally. If you are on Windows, then the PDF-plugin from Acrobat should even display it inline.

    However: A BI tool is only as good as its reports.

    No one I know would be willing to search through even a 100 page report to find nuggets of information. Oh, they will tell their boss they do it regularly, but heck they do.

    Use parametrization to deliver targeted information to your users. Most users only care about a summary and maybe some local information related to their job. Sales people for the US usually dont need sales data for Europe (except for inter-departmental competitions - so let them filter to the bits they need to get their job done.

    Why not change your long list report into a smaller summary report, where users can drill to a detailed report (via drill-linking) if necessary?

    Make that summary report smart - indicate critical changes (10% less sales than last moth) or critical states (we are over budget!) by using colors or other indicators. Use charts or spark-line graphs to get visual information into the report. People are bad at reading through lists, a good chart compresses 1000 lines of data into a single picture.


    In a good BI setup, huge reports only exist for archives. Banks need to print massive reports for regulators - see above on whether they are read - but they dont browse them interactively. They are just stored on disk or tape.

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