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Evernote blog: WhySQL?

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Re: Evernote blog: WhySQL?

#11

Post by morganpyne »

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.

Simple reliable replication has been a huge differentiator for a long time; enough so to put up with a lot of the other faults of MySQL. Have not revisited Postgres replication in a long time but I have seen that it has been worked on. Anyone with recent experience in both care to explain how the replication of both stacks up in recent versions?

Re: Evernote blog: WhySQL?

#12

Post by morganpyne »

bitdiffusion wrote: post #7

The notebook/note example is weak - in a nosql database you need to design your data structure appropriately to get the level of atomicity you require. Storing an entire notebook in a single document would be the most obvious. I use postgres all the time and sql is great, but poo-pooing nosql because it wouldn't work with your relational structure is not the best idea. Also - I have found a hybrid between nosql (mong…

Well, taking a consistent snapshot for backups is easier when it's in a single source. I know there are ways around this (ZFS!) and not everyone needs synced backups to the millisecond but it can complicate backups (or more to the point - restores)

Re: Evernote blog: WhySQL?

#13

Post by bni »

bitdiffusion wrote: post #7

The notebook/note example is weak - in a nosql database you need to design your data structure appropriately to get the level of atomicity you require. Storing an entire notebook in a single document would be the most obvious. I use postgres all the time and sql is great, but poo-pooing nosql because it wouldn't work with your relational structure is not the best idea. Also - I have found a hybrid between nosql (mong…

What about when you want to find all notes that was made a specific day last month (say for a report)?

Traverse all notebook documents and look at each notes date? Good luck with that.

Re: Evernote blog: WhySQL?

#14

Post by sheff »

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.

EnterpriseDB (who sell a commercialized version of Postgres) have a couple of MySQL vs Postgres white papers on their site, but hidden behind a registration wall : http://www.enterprisedb.com/resources-community/whitepapers-... .

Robert Haas, a Postgres committer , occasionally blogs about comparisons : http://rhaas.blogspot.com/search/label/mysql

Theres also http://www.wikivs.com/wiki/MySQL_vs_PostgreSQL

Historically , MySQL has been more widely available on low end web hosting plans, so its what a lot of people first use when they start using databases, and a lot of web apps, such as Wordpress, support it exclusively.

Until a year or two ago, only MySQL had built in (if occasionally fragile) replication which made it popular for that reason alone. Postgres now has robust replication, with new features coming down the pipeline soon : http://www.depesz.com/2011/07/26/waiting-for-9-2-cascading-s....

I prefer Postgres, but oddly enough under Oracle theres been some interesting features added to MySQL, which is good for both.

Re: Evernote blog: WhySQL?

#15

Post by [deleted] »

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.

[deleted]

Re: Evernote blog: WhySQL?

#16

Post by tommyd »

bni wrote: post #13
bitdiffusion wrote: post #7

The notebook/note example is weak - in a nosql database you need to design your data structure appropriately to get the level of atomicity you require. Storing an entire notebook in a single document would be the most obvious. I use postgres all the time and sql is great, but poo-pooing nosql because it wouldn't work with your relational structure is not the best idea. Also - I have found a hybrid between nosql (mong…

What about when you want to find all notes that was made a specific day last month (say for a report)? Traverse all notebook documents and look at each notes date? Good luck with that.

If you were to use MongoDB, wouldn't this just be a case of adding an index to the field of the nested child document (i.e. the note within a notebook) you were interested in and then querying on it? e.g. db.notebooks.ensureIndex({"notes.date": 1});

Re: Evernote blog: WhySQL?

#18

Post by opendomain »

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 have a large operational cost and it may not be partition tolerant so if the wrong servers go down, it may cascade to your whole data store.

Re: Evernote blog: WhySQL?

#19

Post by shingen »

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 easy, allowing me to focus my time elsewhere. Ram, bandwidth, and fast storage have gotten substantially cheaper in the last few years, making it that much easier and cost effective to throw hardware at scaling up. For 99.9% of the Web, those hardware resources are expanding in value much faster than traffic is increasing.

(It's understood other developers find it just as easy to take a different approach)

Re: Evernote blog: WhySQL?

#20

Post by true_religion »

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.

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