3 ms·
> You could easily db.products.update({_id: productId}, {$inc: {inStock: -5}, $addToSet: {pendingCarts: {cartId: cartId, quantity: 5, timestamp: new Date()}}}).
by mbell 9y ago
> You could easily db.products.update({_id: productId}, {$inc: {inStock: -5}, $addToSet: {pendingCarts: {cartId: cartId, quantity: 5, timestamp: new Date()}}}).
That is unlikely to work well at much scale. At least last I knew, Mongo docs are limited to 16MB and the entire doc is read then written in cases like this, very slow on large docs. Given the amount of data that may be attached to a `product`, it's not hard to hit these limits.
- weddpros 9y agoPlease do the math... Before this document reaches 16MB, you're bigger bigger than Amazon. If this solution scales up to Amazon scale, that's good enough for me.