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jackb4040today at 10:35 AM1 replyview on HN

I found the article very helpful from a technical perspective, and didn't focus on the number too much, as it could easily be swapped and the decision-making process for when to shard is kinda out of scope.

But I hadn't considered this, so thanks for pushing back. Good to keep in mind their incentives.

I will say, since their product is a proxy whose interface is a single SQL connection, you should in theory be able to do dev queries through that black box, much the same as application queries? What is so scary here that it would require a hundred engineers?


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groundzeros2015today at 10:54 AM

> you should in theory be able to do dev queries through that black box

Because it’s a leaky abstraction which is trying to make guarantees over network connections which are extremely difficult to make within the same kernel.

A few questions I would start with:

- is the system even ACID compliant?

In my reading of this article, no.

- is my sql feature set limited? Will it enforce all constraints? Or are their cross-shard limitations?

For example the article doesn’t discuss transactions or how they would roll back, or how they guarantee a consistent view of data.

Next:

- how does it respond to error?

- how does it respond to load?

This is a complex system and complexity breeds bugs. But now you don’t have the tools or procedures to investigate those bugs because you can’t poke the system at desk with tools. You can’t run experiments; you can’t even see all the data.

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