Cognos Report - export to excel performance issue

[rperwin]

I know this is a pretty open ended question but does anyone know some reasons why a report may take one minute to run as an HTML page, but takes seven - ten minutes to run the same report as an excel ouput?

I even have two separate pages on the report - one page renders when ran as an HTML page and a second page that runs when exporting as an excel output.  The excel output page even has many things removed from it (basically just a data dump) such as prompts, etc.

Thanks in advance.

[RKMI]

Hi,

There can be several factors why the report is running longer in HTML vs Excel. When you generate a report to run in HTML the SQL sent by Cognos can be a sub-select to return first rows (which uses the Query Engine service) where as when you do an export the SQL sent is completely different (which uses batch report services). I would recommend you to capture the SQL when the report runs as HTML and when it runs as Excel then run a Execution plan on the SQL queries.

Another reason it run longer can be if you set up page breaks it first allocates the space in memory so that result of each page is rendered on each page set item and if you have any special formatting such as images or charts the sizes and other formats to be carried over into excel.

Thanks,
RK

[TheCognosDave]

if excel is really slow, just output to csv and open as excel.  should be waaay fast  ;)