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Evernote blog: WhySQL?

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Re: Evernote blog: WhySQL?

#51

Post by brazzy »

true_religion wrote: post #20
shingen wrote: post #19

It's amazing how when you focus on proven (but supposedly boring or old) technology that just works, and works very well, you can devote a lot of other resources to the actual product and usability. Maybe it's the 30 year old in me showing, but I'm sticking with the 'it just works' crowd. Until some other approach provides a staggeringly overwhelming reason to switch. I find scaling up with MySQL to be ridiculously e…

Er... you seem to be implying that people are using NoSQL solutions like Redis, Toyko Tyrant, Elastic Search, etc. for fun but that's not the case. Sometimes you just pick the simplest thing that works and that can be a key value store, data structures in memory, or a lucrene interface. It's a better solution and less fragile than trying to force everything into a relational model.

No, I think he's implying that people are using NoSQL solutions because they've been hyped a lot and are fashionable. And that's most certainly the case (certainly not the only reason in all cases, but most certainly a reason in many cases).

Re: Evernote blog: WhySQL?

#52

Post by oacgnol »

I can imagine that while Evernote has a lot of data to store, it doesn't have the massive amount of concurrent reads that might occur with an equally large web app. Do they publish numbers on read/write usage?

Re: Evernote blog: WhySQL?

#53

Post by karolist »

robinwarren wrote: post #21
true_religion wrote: post #20

Earlier quoted context omitted.

Er... you seem to be implying that people are using NoSQL solutions like Redis, Toyko Tyrant, Elastic Search, etc. for fun but that's not the case. Sometimes you just pick the simplest thing that works and that can be a key value store, data structures in memory, or a lucrene interface. It's a better solution and less fragile than trying to force everything into a relational model.

I must admit that I picked mongodb (+ node) for my latest project for fun. But I then discovered that being able to dump json straight into a datastore without having to create tables etc. first was a great benefit in quickly building something out. So something I did for fun turned out to be the simplest thing which worked. Only I didn't know that when I did it. I think developers who don't occasionally pick somethi…

I'd actually like to do that too but have a hard time wrapping my head around the notion of building a website with node + nosql alone. My understanding is that node is best for realtime chat-like apps.. Is your project web related might I ask?

Re: Evernote blog: WhySQL?

#54

Post by untog »

huggyface wrote: post #40
mapleoin wrote: post #4

Does anyone have a link to a decent comparison between MySQL and PostgreSQL? I'm really wondering why so many people use MySQL, even though it supports a lot fewer SQL features than PostgreSQL.

MySQL was very, very easy to get started with, getting to a cruise quickly. PostgreSQL offered more of a curve. In the Windows world the same is true of SQL Server -- the setup, connectivity, and basic usage is so incredibly easy that it made it the first choice of many teams. This seems incredible -- that products are chosen on such an irrelevant-in-the-long-term basis -- however it has proven true across almost all…

This seems incredible -- that products are chosen on such an irrelevant-in-the-long-term basis

I don't think there is anything too incredible in that. If you want to throw together an idea quickly, get it out there and test response then use whatever technology gets the job done quickest. You can always change later.

Why waste huge amounts of time setting up a technically perfect database for a product it turns out no-one wants?

Re: Evernote blog: WhySQL?

#55

Post by trustfundbaby »

I get where they're coming from, but I do find this to be a little smug :)

See, they haven't run into problems with their setup, as per, MySql 'just works' for them.

What would be interesting and educational (for me anyway) would be a situation where folks that ran into serious problems with their SQL setup despite doing the 'right things' persevered where conventional knowledge would have them switch to a NoSql solution.

tldr; Dog bites man article, would love to hear from someone that actually struggled with a SQL solution and soldiered on.

Re: Evernote blog: WhySQL?

#56

Post by huggyface »

untog wrote: post #54
huggyface wrote: post #40

Earlier quoted context omitted.

MySQL was very, very easy to get started with, getting to a cruise quickly. PostgreSQL offered more of a curve. In the Windows world the same is true of SQL Server -- the setup, connectivity, and basic usage is so incredibly easy that it made it the first choice of many teams. This seems incredible -- that products are chosen on such an irrelevant-in-the-long-term basis -- however it has proven true across almost all…

This seems incredible -- that products are chosen on such an irrelevant-in-the-long-term basis I don't think there is anything too incredible in that. If you want to throw together an idea quickly, get it out there and test response then use whatever technology gets the job done quickest. You can always change later. Why waste huge amounts of time setting up a technically perfect database for a product it turns out n…

The difference between getting competent with Postgresql versus MySQL was just a few hours. In the scale of a project such a difference dissolves into complete irrelevance, yet it was enough to sway many to use MySQL when it was severely deficient comparatively (though with its adoption it saw love that brought it up to if not beyond parity).

The same is true with many technologies and approaches. Projects that consume thousands or tens of thousands of hours, with a toolset chosen because it represented an outset savings of single-digit hours.

Changing in the future is seldom as easy as it seems in those early days.

Re: Evernote blog: WhySQL?

#57

Post by geophile »

luigi wrote: post #26
shingen wrote: post #19

It's amazing how when you focus on proven (but supposedly boring or old) technology that just works, and works very well, you can devote a lot of other resources to the actual product and usability. Maybe it's the 30 year old in me showing, but I'm sticking with the 'it just works' crowd. Until some other approach provides a staggeringly overwhelming reason to switch. I find scaling up with MySQL to be ridiculously e…

It's amazing how when you use recent technology that has been designed and engineered from the ground up for the demands of modern web apps, you can devote a lot of other resources to the actual product and usability.

Modern web apps are applications. Applications, over time, run into many problems that SQL database systems were designed to address:

* The occasional join.

* Complex queries.

* Reporting.

* Schema changes.

* Transactions, with options for trading off strictness and performance.

* Performance problems that are easily addressed using stored procedures.

* Performance tuning with minimal code changes (e.g. adding an index to change the execution plan of a complex query).

* Enforcement of invariants regardless of application code.

Why would you give these up for scalability problems you won't have, with 99.999999% probability?

Re: Evernote blog: WhySQL?

#58

Post by newhouseb »

opendomain wrote: post #18

There are other reasons to choose NoSQL For example, when Craigslist was using mySql and they had to change their schema, it took MONTHS to facilitate the change across all their slaves. You can also have a mixed strategy of using both RDBMS and NoSQL to achieve consistency while being able to be flexible to architecture changes. Lastly- have you looked at total overal cost? Setting up a large cluster with mySql will…

PostgreSQL can do the majority of migrations you would need to make instantaneously (adding columns that can be null, adding/dropping indexes etc). MySQL suffers roughly O(rows) time when changing the schema, but with PostgreSQL now at feature parity for most everything else there's little reason to go NoSQL over something like Postgres if you are worried about schema changes. With respect to fault tolerance, this is only a problem if your dataset outgrows a single master (pretty rare) and you haven't figured out a proper way to shard (most places shard on users, it's pretty hard to believe anything is un-shardable).

Re: Evernote blog: WhySQL?

#59

Post by newhouseb »

mapleoin wrote: post #4

Does anyone have a link to a decent comparison between MySQL and PostgreSQL? I'm really wondering why so many people use MySQL, even though it supports a lot fewer SQL features than PostgreSQL.

I posted this elsewhere in the thread, but I ran some benchmarks on schema changes between the two on 5 million row tables (when deciding to switch) and PostgreSQL completely clobbered MySQL performance wise: https://gist.github.com/1620133. As we recently switched to PostgreSQL, one gotcha is that PostgreSQL uses separate process instead of threads for each connection and so it's slower and more memory intensive to establish new connections so connection pools held application side (such as pg_bouncer) are incredibly important.

Re: Evernote blog: WhySQL?

#60

Post by HarrisonFisk »

rmc wrote: post #24
dabeeeenster wrote: post #17

It helps that they have a perfectly shardable product I guess.

Yes, if you're Google (where any page can link to any other) or Facebook (where a person can friend any other) you wouldn't have this. But lots of businesses that provide software solutions do usually have something that is very localised.

It's a bit funny that you use Facebook as an example since they use sharded MySQL as their primary data store.
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