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Why I Migrated Away From MongoDB

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Re: Why I Migrated Away From MongoDB

#121

Post by pessimizer »

taligent wrote: post #101
gaius wrote: post #48

Earlier quoted context omitted.

The thing with the NoSQL guys is that many of them seem not to be in a position to make an educated comparison. For example, an, uhh, enthusiastic MongoDB advocate recently informed me that MongoDB was superior to Oracle because in Oracle you had to poll a table to see if it changed. Except, no, that isn't actually true: http://docs.oracle.com/cd/B19306_01/appdev.102/b14251/adfns_... - and that document is from 2005.…

This kind of rubbish really needs to stop. Just because you don't agree with or understand their choices does not mean that the majority of "NoSQL guys" are ignorant or uneducated. Some of the biggest companies e.g. Twitter, Foursquare, Google, Amazon all rely on NoSQL. The real issue I see is that by dismissing NoSQL as only for fools RDBMS developers are failing to see why they are popular to begin with. Take Postg…

The majority of NoSQL guys are not Twitter, Foursquare, Google, or Amazon, and Twitter, Foursquare, Google, and Amazon all have plenty of people experienced enough in traditional RDBMS to tell them what things would probably be better in them.

Most NoSQL guys I meet have little to no experience in SQL. Plenty have lots.

Re: Why I Migrated Away From MongoDB

#122

Post by taligent »

gaius wrote: post #117
taligent wrote: post #116

Earlier quoted context omitted.

I guess so will the likes of Facebook, Google, Twitter, eBay etc. Must be amazing to know more about databases than all of the world's biggest companies put together.

Why? The guys at FB or Google are just guys like you and me, don't believe the hype, they are not superheroes or gurus despite their much talked about interview process (the Google interviews I did were a walk in the park compared to GS, btw). Some will know more than me sure, but some'll know less.

Those were only a few examples. I can keep listing companies that use sharding.

The idea that it is some 1980's approach to scaling databases is laughable.

Re: Why I Migrated Away From MongoDB

#123

Post by taligent »

pessimizer wrote: post #121
taligent wrote: post #101

Earlier quoted context omitted.

This kind of rubbish really needs to stop. Just because you don't agree with or understand their choices does not mean that the majority of "NoSQL guys" are ignorant or uneducated. Some of the biggest companies e.g. Twitter, Foursquare, Google, Amazon all rely on NoSQL. The real issue I see is that by dismissing NoSQL as only for fools RDBMS developers are failing to see why they are popular to begin with. Take Postg…

The majority of NoSQL guys are not Twitter, Foursquare, Google, or Amazon, and Twitter, Foursquare, Google, and Amazon all have plenty of people experienced enough in traditional RDBMS to tell them what things would probably be better in them. Most NoSQL guys I meet have little to no experience in SQL. Plenty have lots.

The plural of anecdote is not data. You know that right ? In my case every NoSQL developer I've met had a lot of experience in SQL as well.

But do you have ask why so called inexperienced users are choosing NoSQL in the first place ? Hint: it's because most RDBMS are ridiculously complex and inflexible.

Re: Why I Migrated Away From MongoDB

#124

Post by Firehed »

zemo wrote: post #21
bunderbunder wrote: post #6

Fourthly, and this one completely blew my mind - somewhere along the stack of mongodb, mongoid and mongoid-map-reduce, somewhere there, type information was being lost. I thought we were scaling hard when one of our customers suddenly had 1111 documents overnight. Imagine my disappointment when I realised it was actually four 1s, added together. They’d become strings along the way. I've been having a similar problem…

Mongo accepts the data you give it. If you have a type-conversion error, it's in your application layer. I use Mongo daily and have never seen this problem, because I'm using a statically typed language. This seems like more of a complaint about Ruby than Mongo. I use Mongo daily on a Go project, and I actually think it's pretty annoying; I'm not trying to be a Mongo apologist, but ... this type conversion argument d…

Yeah - this sounds more like a problem where someone was using a loosely-typed language that uses "+" for both addition and concatenation.

Re: Why I Migrated Away From MongoDB

#125

Post by jeremyjh »

gaius wrote: post #117
taligent wrote: post #116

Earlier quoted context omitted.

I guess so will the likes of Facebook, Google, Twitter, eBay etc. Must be amazing to know more about databases than all of the world's biggest companies put together.

Why? The guys at FB or Google are just guys like you and me, don't believe the hype, they are not superheroes or gurus despite their much talked about interview process (the Google interviews I did were a walk in the park compared to GS, btw). Some will know more than me sure, but some'll know less.

Just guys like you or me except they build systems with billions of page views a month.

Re: Why I Migrated Away From MongoDB

#126

Post by jeremyjh »

mrinterweb wrote: post #118

I find this article to be more a reflection of a NoSQL newbie's failed foray with a document database that later realized that the grass is not as green as originally perceived. The developer realized that he does not like map-reduce and missed not having joins. I don't see how this person's failed experience with MongoDB is a reflection on MongoDB. I think the recent popularity of MongoDB bashing is maybe a testamen…

Yes, MongoDB is more of a general-purpose database with lots of features that remind us of relational databases. It is a purpose-built application database for applications that would otherwise almost certainly be built with a relational database. As they get deeper into their project and find out how some of the trade-offs play-out their self-doubt is always about "should we just go relational" - no one is staying up all night wondering if they should migrate to Riak. If you start out with Riak you almost certainly know why and are using it in a very specific context.

Re: Why I Migrated Away From MongoDB

#127

Post by jeremyjh »

otterley wrote: post #65
trafficlight wrote: post #61

Earlier quoted context omitted.

>> "You have to put the whole dataset on RAM?" I'm pretty new to the whole database thing, but how is MongoDB different from Postgres or Mysql in this respect? In a traditional database, the data is pulled directly from the hard drive. Why does Mongo suffer a performance hit and Mysql doesn't?

Because MongoDB mmap(2)s its backing stores into its process memory space. It's a naive approach to persistence - it's very fast and simple, but if you overcommit (i.e. you store more in the database than you have memory available), page-thrashing results. MySQL's InnoDB table engine, on the other hand, uses direct I/O (in the recommended scenario) and manages the buffer pool independently of the kernel. Its buffer p…

Its hardly naive, it is optimized for an application that needs to keep its entire working set in RAM, that is why sharding is so fundamental to the design. Not all apps need that which is once again...

Re: Why I Migrated Away From MongoDB

#128

Post by reinhardt »

taligent wrote: post #123
pessimizer wrote: post #121

Earlier quoted context omitted.

The majority of NoSQL guys are not Twitter, Foursquare, Google, or Amazon, and Twitter, Foursquare, Google, and Amazon all have plenty of people experienced enough in traditional RDBMS to tell them what things would probably be better in them. Most NoSQL guys I meet have little to no experience in SQL. Plenty have lots.

The plural of anecdote is not data. You know that right ? In my case every NoSQL developer I've met had a lot of experience in SQL as well. But do you have ask why so called inexperienced users are choosing NoSQL in the first place ? Hint: it's because most RDBMS are ridiculously complex and inflexible.

The last line sounds pretty familiar after replacing "NoSQL" with "PHP" and "RDBMS" with "decent languages".

Re: Why I Migrated Away From MongoDB

#129

Post by daleharvey »

gregjor wrote: post #64
gaius wrote: post #48

Earlier quoted context omitted.

The thing with the NoSQL guys is that many of them seem not to be in a position to make an educated comparison. For example, an, uhh, enthusiastic MongoDB advocate recently informed me that MongoDB was superior to Oracle because in Oracle you had to poll a table to see if it changed. Except, no, that isn't actually true: http://docs.oracle.com/cd/B19306_01/appdev.102/b14251/adfns_... - and that document is from 2005.…

Programming is more like fashion than science in this regard. Every decade or so something truly new happens in the software world. All the rest is mostly sound and fury, signifying nothing. If you're young or new to programming it's easy to mistake the buzz around things like NoSQL for innovation when they are usually re-discoveries of old (and often discarded or obsolete) ideas dressed up in new clothes. There's al…

I cannot remember a more aggravating discussion on Hacker News.

A lot of people who are working with / building and using 'NoSQL' databases are the very same people building the RDBMS tools that you are so eager to defend.

You have stated elsewhere that you do not know anything about 'NoSQL' stores, so instead of insulting a huge number of people far more experienced than yourself, why dont you attempt to learn? (or at the very least, avoid disregarding the thoughts of a huge sector of the industry)

Re: Why I Migrated Away From MongoDB

#130

Post by pessimizer »

taligent wrote: post #123
pessimizer wrote: post #121

Earlier quoted context omitted.

The majority of NoSQL guys are not Twitter, Foursquare, Google, or Amazon, and Twitter, Foursquare, Google, and Amazon all have plenty of people experienced enough in traditional RDBMS to tell them what things would probably be better in them. Most NoSQL guys I meet have little to no experience in SQL. Plenty have lots.

The plural of anecdote is not data. You know that right ? In my case every NoSQL developer I've met had a lot of experience in SQL as well. But do you have ask why so called inexperienced users are choosing NoSQL in the first place ? Hint: it's because most RDBMS are ridiculously complex and inflexible.

The plural of insulting everyone's intelligence who disagrees with you is not authority.

>But do you have ask why so called inexperienced users are choosing NoSQL in the first place? Hint: it's because most RDBMS are ridiculously complex and inflexible.

If we're going to have a cliche fight, this one is called having your cake and eating it too. Either inexperienced users are gravitating to NoSQL or they aren't.

Operating under the assumption that they are, I'd say it's both because they can interact with them without an impedance mismatch; also because they are flat, they are easy to visualize. Another reason might be because they don't have to put a lot of thought into their schema, which would involve new concepts that would take a little time to learn. The biggest reason in my eyes would be that they don't know how big a performance hit they're taking in a write-heavy environment.

In very read-heavy environments with wide heterogeneous queries that you would end up denormalizing in 18 different ways anyway? They could be doing it because they're smart and have done their research. I love NoSQL.

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