So the 10,000,000 million cells limit is indeed a limit on a Google Sheets. There are things you can do to help yourself though and one of the first is to delete any columns in your sheets that are not in use and don’t have any headers. This will leave you with just the correct amount of columns needed to run your app. All those columns and rows that are empty still count towards the 10,000,000 limit.
Another thing you could do is to take your most full sheet and copy it out to its own NEW Google Sheets file. Then you can swap the data source in your app to point to this new file instead…remember to rename the copied sheet to remove the ‘Copy of’ prefix that Google adds when copying from one workbook to another.
You can actually do this for ALL of the sheets within the workbook so that each table in your app can point to its own Sheet. You will gain a huge amount of memory this way. There will be a little trade off in the speed that your app will start up as now all of the tables are separate and not stored in the same workbook, however, that’s a small price to pay for all the extra data you can process.
Start to experiment with Cloud SQL though as you go forward. The sync speed increase is very noticeable when using a proper database compared to a spreadsheet and AppSheet sort of makes it easy to ‘convert’ your sheets tables into a Cloud SQL table once you have set up the initial requirements of having a database defined and ready to accept new tables. It’s very easy to swap back and forth between data sources although I would only convert sheets to database once you have finished developing the app as it is MUCH easier to chop and change a spreadsheet around while developing and you don’t need to know any SQL.
Another back of the envelope calculation to know the cells being used by a sheet will be to multiply the number of populated columns in a sheet by the number of populated rows.
So if a sheet has 35 columns and 8000 rows populated, the cells populated are 8000*35= 280,000 or 280 K cells.