SQL Databases Don't Scale
adam.blog.heroku.com
SQL Databases Don't Scale
1–10 of 112 posts
Re: SQL Databases Don't Scale
#2This article is about relational databases that you read from and write to. It isn't SQL-specific. It's a good article, not another "SQL is obsolete" as you might think from the title.
Re: SQL Databases Don't Scale
#3"Sharding kills most of the value of a relational database."
I can appreciate the point the author makes about partitioning schemes requiring heavy integration with the business logic, but I disagree with the claim that sharding doesn't work.
It's probably more accurate to say that sharding only works well if you design your database very carefully, or just get lucky about how your data model maps to sharding schemes. A bad sharded database can probably hobble your app, but a good one does get you remarkably close to true horizontal scaling.
In my experience, at least.
Re: SQL Databases Don't Scale
#4I thought it was a good summary of the problems facing SQL databases as organizations grow. However I would have appreciated some solutions to the problem.
Re: SQL Databases Don't Scale
#5In the final paragraph he compares himself with Capt Kirk, facing the Kobayashi Maru: "we can only solve this problem by redefining the question."
Well, perhaps that's as difficult as solving the "SQL scalability that 20 years of brilliant programmers haven't solved"?
...because he declines to attempt to reframe the question.
[ or maybe he's leaving us wanting more: like his next post? ]
Anybody up for reformulating the question?
Re: SQL Databases Don't Scale
#6I thought it was a good summary of the problems facing SQL databases as organizations grow. However I would have appreciated some solutions to the problem.
I think one of the points made at the end was that there kinda isn't one - people have been trying to come up with the perfect solution to scaling RDBMS's for ever and the current state of the art (pretty much) is as described in the article - i.e, not great.
People with really massive MySQL setups (eBay, for example) basically just do a huge amount of the stuff described here, but with lots of message-queue type stuff to glue it together and loads of hard work; i.e. you can make it scale but it's really really hard work because RDBMS's aren't inherent scalable.
Re: SQL Databases Don't Scale
#7RAID doesn't meet his definition of "scalable" because it has a central controller.
This whole post could be summed up as "ACID doesn't scale", which has been proven. Consistency, Availability or Partition Tolerance; pick two (http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.20.1...).
Good introduction to non-ACID databases: http://highscalability.com/drop-acid-and-think-about-data
Re: SQL Databases Don't Scale
#8"Sharding kills most of the value of a relational database." I can appreciate the point the author makes about partitioning schemes requiring heavy integration with the business logic, but I disagree with the claim that sharding doesn't work. It's probably more accurate to say that sharding only works well if you design your database very carefully, or just get lucky about how your data model maps to sharding schemes…
If you data model maps well to sharding, it maps well to distributed databases, and you're not gaining much by being on an RDBMS. I think the point they're trying to make is if you're going through the contortions to shard a relational database, you're better off just doing it in a distributed database in the first place.
Re: SQL Databases Don't Scale
#9"Sharding kills most of the value of a relational database." I can appreciate the point the author makes about partitioning schemes requiring heavy integration with the business logic, but I disagree with the claim that sharding doesn't work. It's probably more accurate to say that sharding only works well if you design your database very carefully, or just get lucky about how your data model maps to sharding schemes…
Sharding means you can't do "select * from a join b using (k)" unless you can prove the a record and the b record will always be hosted on the same shard. So of course you often have to write application code that knows where they are and goes and gets them separately. But that's precisely the problem that relational databases were developed to solve for you.
Then there's the whole distributed transaction thing, which is so painful that some people just live with wrong answers instead.
Re: SQL Databases Don't Scale
#10SQL databases are fundamentally non-scalable, and there is no magical pixie dust that we, or anyone, can sprinkle on them to suddenly make them scale.
I find this claim laughable. If the databases Mr. Wiggins chooses to work with fail to meet his scalability requirements, perhaps he should consider different databases. Scalable SQL databases have been around for over 3 decades.