Re: MySQL 8.4 Secure Export and Import

[Phillip Ward]

(I am not a Lawyer, but ...)
I would suggest that you don't need any kind of "secure file sharing" here.

Both of these alternatives start out with a MySQL Export.
The result of that should be a plain text, human-readable, SQL file; a script containing "CREATE ..." statements.
That's good, because there's nowhere to hide anything "nasty".

Export only the schema structures - the table & index definitions.
Do not export any Data from any tables.

Send the Developer this file.
It contains no Data, therefore no Personal Data to worry about and nothing proprietary, since they're just SQL scripts creating tables, indexes and the like.
The Developer should be able to synthesise their own data when they want to carry out performance testing against their modifications. If they can't, or [keep] ask[ing] for a copy of your database, consider finding a better Developer!

Have the Developer send back the same, MySQL export of only their modified schema structures - no data.
When they do, you can use any text "differencing" program to compare what you sent them with what they sent back. The "difference" will be their modifications. If they send you anything else, refer them to the written Contract and the result you are expecting from them (i.e. what you are prepared to pay them for).

Apply their suggestions to your Test database (you do have one, don't you?) and verify that their suggestions actually have the desired effect on your system's workload. (No two systems are exactly identical.)

Regards, Phill W.