Raw Data format from SP

[Derek McKinnon]

I am writing a stored procedure to return a table of data for a webpage. MysQL 5.7 (although 8 is not far off).

The data set I return is basic. Three INT fields.
ChildID
ActivityID
LevelID

Speed is critical. The webpage needs to load around 0.1 seconds.

When we go live, there will be no data, so performance will be easy. However within about 6 months, I could be returning up to 15,000 rows of data.

The UI guys have requested a JSON return.
eg.
[
1543: [
{ActivityID: 436, Level: 3},
{ActivityID: 943, Level: -1},
…etc
],
2680: [
{ActivityID: 436, Level: NULL},
{ActivityID: 943, Level: 2},
…etc
],
]

Which made me realize I have never actually seen what table data looks like as it travels across a network.

Surely it must be more efficient than the JSON format? I did a google search, but can't find anything.

Can anyone give me some guidance as to what table data actually looks like when it is transferred out of MySQL.

Thanks
Derek