Input from node-mbtiles

[tmcw]

Saw this comment in node-mbtiles - is there a more specific concern here that we can address, @kkaefer?

[kkaefer]

The "design flaw" I'm talking about is that we have a shard table linking to both map image and grid. This makes updates more complicated because we have to take into account that one of the two might be filled in, or the row doesn't exist at all. Separating these into two tables would make it easier for mbtiles to create and continually update files.

[tmcw]

This is outside of the spec: this specification is an interface that your database needs to implement, not the underlying structure. Closing.