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Why I Migrated Away From MongoDB

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Re: Why I Migrated Away From MongoDB

#101

Post by taligent »

gaius wrote: post #48
gregjor wrote: post #42

You were fortunate to recognize that MongoDB was the wrong tool for your job, and lucky to be able to move to Postgres instead of continuing to throw your time and effort away. I see the ad hominem "you're an ignorant idiot" attacks already started, along with advice like using regexes to do case-insensitive searches. Watching the NoSQL "movement" encounter the problems RDBMSs fixed 20 years ago and then hand-wave an…

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 PostgreSQL for example and how difficult it is to shard/replicate compared to CouchDB or MongoDB. This is an area PostgreSQL should see as an opportunity for improvement.

But dismissing huge groups of people as uneducated just makes you seem uneducated.

Re: Why I Migrated Away From MongoDB

#102

Post by ww520 »

Wow, the first comment on the blog is so vile. He angrily blamed the "victim" (OP) as a talentless developer.

Tools are enablers and supposed to make ordinary people rock star. If it takes a rock star to use a tool, the tool fails.

Re: Why I Migrated Away From MongoDB

#103

Post by trafficlight »

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…

Ah, ok. That makes a lot more sense. Thank you.

Re: Why I Migrated Away From MongoDB

#104

Post by saurik »

zemo wrote: post #67
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.…

MongoDB is disproportionately liked by the inexperienced. There are things to like about it, and being able to have sparse secondary b-tree indexes on arbitrary data is, overall, pretty rad. For prototyping, being able to just toss some shit in there, especially when your data comes from an external service and you're not in control of your incoming data (very common these days), it works great for simple use cases a…

(Not a response, but related as an FYI: you can easily do sparse secondary b-tree indexes over secondary data using PostgreSQL using predicated functional indexes.)

Re: Why I Migrated Away From MongoDB

#105

Post by voidr »

Relational databases are awesome if you are not dealing with huge amounts of data that your current hardware can't handle the relational way. There are some cases where you have a ridiculous amount of data(rows) and you simply can't store that in a relational database and you are happy to live without the benefits of relational databases.

If you have millions of rows, you are probably better off with something like MongoDB, if you need to search that, you should probably use something like Sphinx or Lucene anyway. But if you know that you won't have too much data for the forceable future, you should use relational databases. OR you could simply use both.

Re: Why I Migrated Away From MongoDB

#106

Post by taligent »

zemo wrote: post #67
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.…

MongoDB is disproportionately liked by the inexperienced. There are things to like about it, and being able to have sparse secondary b-tree indexes on arbitrary data is, overall, pretty rad. For prototyping, being able to just toss some shit in there, especially when your data comes from an external service and you're not in control of your incoming data (very common these days), it works great for simple use cases a…

You deploy a database without doing a spike or clearly without reading the documentation. Because it is well known that MongoDB by design is ill-suited for doing lots of join between tables. It is much better thought of as a document store.

So who is the inexperienced one here ?

Re: Why I Migrated Away From MongoDB

#107

Post by nnnnnnnn »

ilaksh wrote: post #79
nnnnnnnn wrote: post #78

Earlier quoted context omitted.

"On your home page you imply that you can automatically OCR arbitrary handwritten receipts into an analyzable format. No one can do that. That is your problem" Jeez, lay off the confrontational tone. He doesn't say anything about OCR. Maybe he's using humans to do data entry? In any event, it's completely irrelevant to the topic of databases.

I notice you ignored all of my several very specific points directly related to his issues with the database system and your only comment was a criticism about the tone you perceived. OK, maybe he is using humans to do data entry. The home page to me implies that the process is automatic, but I guess it doesn't rule out the possibility of humans doing data entry when he says 'tag and categorize'. But if he is using h…

It's because I have nothing to say about the database stuff. Why are you so adversarial? I'm not here to cross swords with you; I don't have an opinion on the matter.

But I did notice your rudeness, and you're now being rude to me. Totally uncalled for.

Re: Why I Migrated Away From MongoDB

#108

Post by [deleted] »

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…

[deleted]

Re: Why I Migrated Away From MongoDB

#109

Post by gregjor »

voidr wrote: post #105

Relational databases are awesome if you are not dealing with huge amounts of data that your current hardware can't handle the relational way. There are some cases where you have a ridiculous amount of data(rows) and you simply can't store that in a relational database and you are happy to live without the benefits of relational databases. If you have millions of rows, you are probably better off with something like M…

There may be cases where non-relational databases are the right solution, but unless you are using a toy RDBMS millions of rows is not considered a lot of data. Millions of rows added every day... now you're talking. Oracle handles that kind of thing just fine.

Re: Why I Migrated Away From MongoDB

#110

Post by taligent »

gregjor wrote: post #87
blaines wrote: post #82

Earlier quoted context omitted.

Respectfully, I believe your comment is not very open minded. I believe the obvious answer is "Of course there's a use case!", just like there's obviously a use case for RDBMS, NoSQL (Mongo, Cassandra, BigTable, Redis, etc) serves a purpose. I'll give you a couple examples. Google stores a huge amount of data in BigTable [1] which is fundamental for the operation of Gmail at scale. Another, Facebook initially used Ca…

I wrote "I don't know if there's a use case. I have never had one come up in my own projects." I don't work for Facebook or Google, perhaps they have a use case. I guess I could assume there's a use case because the tools exist and people use them, but in my experience I have not had a need for Mongo or any NoSQL database. I'm not dismissing the tools out of hand -- I haven't used them except to play around with tuto…

> I haven't used them except to play around with tutorials.

And yet you feel the need to lecture others on their choices ?

Wow you are something.

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