This is a sticky topic, providing a list of frequently asked questions and answers in one handy post. It is a work-in-progress, so if you have any questions and answers you feel should be reflected here, please ask one of the moderators or administrators to add them to the topic.
MF.
- Q. When I create a list report and add a layout calculation in the page footer to show the total number of report pages, when I run the report interactively and use the HTML rendering type, the page numbers in the page footer are displayed as 1 of ? ,2 of ? and so on. When I render the same report as PDF or Excel, the page numbers display as 1 of 9, 2 of 9 and so on, which is exactly what I need. Is there any solution for this when rendering as HTML?
A. The reason for this is the way report is rendered: When rendering interactively in HTML, the report is rendered one page at a time, so the engine does not know in advance how many pages your report output is going to span. When you render your report as any other format (PDF, Excel etc), the whole report output is rendered and thus the engine knows how many pages the report output spans. If you use the "Run with options" button for your report from Cognos Connection, select "Save the report" and choose HTML as the rendering type, the entire output will be generated as HTML pages, with correct page numbering, and your users can then click to view this saved output.
- Q. When I run a report interactively in HTML format, it returns output in a short time. When I run the same report interactively in PDF or Excel format, it is taking a very long time to return output. Please could you explain why this is happening?
A. When you render as HTML (interactively) only the first page is initially rendered - so you're not retrieving all the data. If you click the "next page" link, the data for the next page is retrieved then the page is rendered. When rendering as PDF (or Excel or CSV or XML) the whole output is rendered in one go, so all the data has to be retrieved before you can view the output.
- Q. How do I post a new question in the correct forum section of the Cognoise web site?
A. i. Open a web browser session
ii. Navigate in your web browser to the home page of Cognoise - http://www.cognoise.com/community
iii. If not already signed in, enter your user name and password in the login fields in the top left corner of the page and press "Login"
(https://image.ibb.co/dofmxk/New_Post_1_zpszcijtrf4.png)
iv. Select the section relating to the product you are using - for example, click on Cognos 10 BI
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v. Select the child board of the particular component you want to ask a question about - for example click on Report Studio
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vi. To start a new topic (ie to ask a new question) press the "New Topic" button in the top right corner.
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vii. Enter a subject for your question, enter the text of your question, then press "Post" in the bottom right corner.
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- Q. Detail filters work fine when writing my report against a relational package. Why shouldn't I use them when writing reports against a dimensional package?
A. In super-simple situations, you might find that detail filters against a dimensional source will give you the right answer. Be under no illusion, though, as soon as you try to extend this and do more, you're in DEEP trouble using detail filters with your OLAP source. To see why, I have great pleasure in pointing you to the witty, informative words of Paul - one of the all-time Cognos BI rockstars...
http://www.cognoise.com/index.php/topic,18290.msg53585.html#msg53585
http://cognospaul.com/2012/01/29/why-detail-filters-should-never-be-used-in-olap/
- Q. How can I tell if I am using a relational or a dimensional package when authoring my report?
A. Relational and dimensional packages appear differently in the package tree, and looking for some key structures can help you easily identify which you are using.
A relational package comprises Query Subjects (blue rectangle in the image below) and query items (orange rectangle in the image below). If you see your data arranged in this way, you are using a relational package.
(https://image.ibb.co/hTvVOQ/Package_Rel_zpsr2oddnao.png)
A dimensional package comprises dimensions, hierarchies, levels and members. There are two ways of viewing your package - either as a structural view, or as a member tree view.
Below is an image of the structural view. You can see Dimensions (purple rectangle in the image below), Hierarchies (green rectangle in the image below) and levels (red rectangle in the image below). You will also see a Members folder for each hierarchy and within each level, and the measures are grouped together in one place.
(https://image.ibb.co/dee1V5/Package_Dim1_zpsrhtluirp.png)
Below is an image of the member tree view. You can see hierarchies (grey rectangle in the image below) and members (brown rectangle in the image below). Again, the measures are grouped together in one place. You can use the leftmost and second-to-leftmost buttons above the tree to toggle between member tree view and structural view.
(https://image.ibb.co/i7VVOQ/Package_Dim2_zpsq5lugnwb.png)
How about something to explain why interactive HTML may render quickly but the same thing for PDF or Excel is very slow. I think a lot of new users don't understand that HTML output may be fetching only part of the result set and then fetching/displaying subsequent portions as you page down. When rendering PDF or Excel (or even saving/emailing in HTML format) the entire result set must be fetched and rendered, thus taking longer.
Thanks Lynn! I've added this as Q2 above. MF.
Sometimes there are new authors who aren't sure if their package is relational or dimensional. It might be a good FAQ item to explain how they can easily tell.
Thanks Lynn! Another great suggestion! This has been added as Q5 above. MF.