Q:

What causes Excel export from SQL Server Reporting Services to produce an abnormally large file?

We have are relatively simple Reporting Services report that our users commonly export to Excel. I've noticed that the files produced by the Excel export seem unusually large. If I open one of these files and just click save, without making any changes, the file size reduces to about half of it's previous size. Has anyone else run into this and is there a known workaround?

A:

You've mentioned that the report is relatively simple, but this is important to check. The export to Excel will go to extraordinary lengths to try and maintain how your report looks.
If you have lots of different borders or colours (particularly if different formatting is determined by the data in your report) this will bloat the file.
Also check if many columns with very small and unusual sizes are created in the exported worksheet. The export does this to try and match alignment in Excel with the original report.
Try recreating your report as a basic table with no formatting or headers/footers and see if you can reproduce the problem. If Excel's behaviour is acceptable then add each piece of formatting back until it goes awry. Please let us know what you find.

