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> Backwards compatibility constraints mean that ... It is not possible to add a sixth "JSON" type.

What? Can someone explain why backward compatibility prevents future versions from added functionality? I guess someone somewhere is doing some case statement on the type of thing in a column? That's a pity... SQLite doesn't even have a datetime type. Now I'm wondering if these are related.

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This is just an educated guess, but it could be an issue with the on-disk record formats. A quick look here: https://www.sqlite.org/fileformat2.html shows that variable length types like BLOB and TEXT are denoted by a type code value greater than 12 that is even or odd (respectively). The only wiggle room looks like values 10 and 11, but of course there would have to be some completely separate way of denoting the size.

That doesn't explain backwards compatibility issues unless what they're saying is they want stuff created in SQLite 3 to work with SQLite 2. The policy doesn't seem to say that though. It's probably just hard to figure out.

http://www.sqlite.com/formatchng.html

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