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0 pointsphamilton9y ago0 comments

> What sort of database is effectively useless for querying?

Cassandra, Riak, Voldemort, HBase, Bigtable, Azure Table Storage, and many other implementations of wide column stores have similarly limited querying.

I'm also not sure what you mean by the limiting scaling model. I can go from 0 to 160k reads/second by turning a knob, and 160k is only the default limit (you can request higher limits).

It is not a document store. It's a wide column store. Use it for the right job and it does very well. Treat it like postgres and you are gonna have a hard time.

0 comments

tech29y ago

The price for that 160k is horrifying though, esp. if the requirement is bursty rather than continuous.

lostcolony9y ago

Which is why you turn the knob back down when you stop being bursty.

But yes, it's pricy. It may not be the best fit for some. Hopefully by the time you're taking 160k writes per second you have a solid business model. I mean, Twitter peaked at around 8000 tweets per second. What are you doing that requires 160k, and do you really need to be storing it?

danek9y ago

It's probably an indication that your use-case is not a good fit for dynamo, or that you didn't adapt your use-case to dynamo, you're doing something "wrong" like trying to use it as a relational database. I've experienced some of these pains as part of my dynamo learning curve.

For example by changing my query strategy I was able reduce the provisioned write units from 1900 to 150 (write units dominate the cost).

phamiltonOP9y ago

Ignoring reserved prices, it is $10.40/hr (these are eventually consistent reads, so half the cost of consistent ones). That puts it roughly on par with an RDS postgres r3.8xlarge instance with 10k provisioned IOPS.

Sure, you likely have more than one table on RDS, so that cost is amortized, but when you get to the scale where you need 160k reads/s, you aren't going to have much more than that one dataset in a single instance.

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