You can increase the page size [1]. That will increase the size of the B tree nodes [2] (and other pages too but that's probably what you want):
> The upper bound on [the number of keys on an interior b-tree page] is as many keys as will fit on the page.
I think a tricky part of this idea would be the locking. Usually SQLite relies on the locking of the underlying filesystem. You could add your own mechanism that causes a lock to be assigned to a single client connection, but what if it never unlocks? (On a single machine you can tell if the client process has crashed.) You could add a timeout but what if the client process then does respond?
> The upper bound on [the number of keys on an interior b-tree page] is as many keys as will fit on the page.
I think a tricky part of this idea would be the locking. Usually SQLite relies on the locking of the underlying filesystem. You could add your own mechanism that causes a lock to be assigned to a single client connection, but what if it never unlocks? (On a single machine you can tell if the client process has crashed.) You could add a timeout but what if the client process then does respond?
[1] https://www.sqlite.org/pragma.html#pragma_page_size
[2] https://www.sqlite.org/fileformat2.html#b_tree_pages