[ergo98]

>You can't compare memory-only db performance against a disk based db, period.

But...you can. What do you mean you can't compare? Clearly you can, however mortified you might be at that prospect.

A reasonable motorcycle can go from 0-60 in about 4 seconds. A reasonable car can do it in about 9 seconds. But you need to carry two passengers so the car is your only option, and such a comparison doesn't matter to you, but to a lot of people it's interesting if ultimately they just want to get from A to B as quickly as possibly. Then again if you want to transport goods maybe you need a truck, or a train.

This is so silly. Wait -- hand wavy -- that's right, nothing can be compared to Cassandra but pure love itself.

[mileszs]

I don't think it's hand-wavy. I think you're upset about something else related to Cassandra that perhaps you read recently -- not tlack's comment. Suggesting it would make more sense to compare an in-memory data store to another in-memory data store would be a more interesting comparison seems a perfectly valid suggestion.

"This is so silly. Wait -- hand wavy -- that's right, nothing can be compared to Cassandra but pure love itself."

C'mon, man. That doesn't further discussion. That sort of statement serves only to incite anger.

[ergo98]

> I think you're upset about something else related to Cassandra that perhaps you read recently

Huh? No, I love Cassandra. She's a beaut.

tlack didn't say "it would make more sense to compare an in-memory data store to another in-memory data store". They said "You can't compare memory-only db performance against a disk based db, period.". There's a pretty profound difference between those two statements.

[tlack]

Of course you can compare them. You can compare the speed of Oracle on a huge RAC cluster vs. text files on an Amiga 500 floppy drive. But no one would, because it's stupid and worthless. I guess that's what I meant: this is a stupid and worthless article.

[jhugg]

I didn't mean to claim anyone will be struggling to decide between VoltDB and Cassandra and then choose VoltDB based on the benchmarks we did. I think that's as ridiculous as you do.

Our point, which perhaps I made poorly, was twofold. 1. You can be both fast and SQL. Nothing about the language itself was ever the bottleneck. 2. VoltDB isn't just for big complicated transactions. You can use SQL for KV-type workloads and perform.

There's 100 other reasons to pick one data layer over another, and the best tool will be different for different problems.