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From Mister Donut <>
Subject Re: The Blog
Date Mon, 09 Feb 2009 10:28:57 GMT
Hello Patrick,

I am writing down thoughts as they come.
I would appreciate if you tried to follow.
Yes, I realize storing comments inside the entry is a bad idea.
I was following an introduction to CouchDB.

> Sure, use the view to get all comments and specify count=0.
> You can get them in one query, just group comments by post_id in your map reduce query.

I don't think you understand my point.
Yes, I know. Maybe you should re-read.
You still need one lookup for every blog entry on a page.
And there is no way you can ever store the comment count inside the blog entry.

> startkey, endkey and limit.

That sounds so great. But wait. LIMIT.
I know that from SQL. It doesn't scale.
Jumping to page 1234567 of ten million. Please, no.

And you cannot, ever, group items based on a variable criteria.
For example in batches of around one hundred.
Which solves pagination.
A view cannot provide that. But again, there is no way you can "manually" do it.

> Anything!

I challenge you. Build me a counter!
No seriously.

Pick one:
GROUP BY, LIMIT, _rev to fake transactions. Uh. Oh. Hello SQL?
You know something magical that allows you to avoid _rev.

So please tell me.
What exactly can I use CouchDB for that uses its strengths,
and not weaknesses? I am honestly not trying to make a fool of anyone.
The CouchDB book seems only to justify the design choices.
The Wiki is completely unhelpful.
Every time it gets interesting.
It stops. That second article, that would certainly enlighten me.
Yes, how, would you go about implementing that?

I don't see how you can make it work but by using an awful lot of merging logic.
Isn't that why you use a RDBMS in the first place?

> It's already there.

You're right, I missed that one. It's even more scary.

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