We have a large amount of code which captures a data set and then gives it to a user as a spreadsheet. We've been using COPY TO (filename) XLS and, for the most part,
this has worked well for us. We haven't run into too many issues with large data sets (these were broken down into multiple sheets and have a different routine if the dataset contains memo fields.

I'm now running into situations where we are going to have a significant number of datasets with more records than COPY TO XLS can handle and I'm looking for advice on the easiest way to turn them into XLSX files.

I have some ideas (do the first chunk as XLS. Convert it to XLSX. Do the extra chunks as XLS and then COPY/PASTE the records) but they feel clumsy and I'm sure there has to be a better way.

All feedback appreciated.

........... Rich