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Moving From CouchDB To MySQL
itwbennett writes "Sauce Labs had outgrown CouchDB and too much unplanned downtime made them switch to MySQL. With 20-20 hindsight they wrote about their CouchDB experience. But Sauce certainly isn't the first organization to switch databases. Back in 2009, Till Klampaeckel wrote a series of blog posts about moving in the opposite direction — from MySQL to CouchDB. Klampaeckel said the decision was about 'using the right tool for the job.' But the real story may be that programmers are never satisfied with the tool they have."
Of course, then they say things like: "We have a TEXT column on all our tables that holds JSON, which our model layer silently treats the same as real columns for most purposes. The idea is the same as Rails' ActiveRecord::Store. It’s not super well integrated with MySQL's feature set — MySQL can’t really operate on those JSON fields at all — but it’s still a great idea that gets us close to the joy of schemaless DBs."
And in another three years they will switch to whatever is the coolest up-and-coming storage solution. Incompetent developers will always be incompetent developers.
That's actually a rather insightful point...
If your application fits well with the methodologies of a traditional RDBMS, use a traditional RDBMS, and hire people who are trained and experienced in using those methodologies to their full potential.
If you're dealing with the latest Big Data paradigms and designs, where you can sacrifice some of the rigidity of a RDBMS to gain some flexibility and cheaper scalability, use a NoSQL database, and hire people who aren't stuck in their old RDBMS ways.
You do not have a moral or legal right to do absolutely anything you want.
PostgreSQL 9.2 beta improves scalability, adds JSON
http://www.h-online.com/open/news/item/PostgreSQL-9-2-beta-improves-scalability-adds-JSON-1573815.html
You can get json support using the PLV8 extension http://code.google.com/p/plv8js/wiki/PLV8
or altenatively you can use the hstore data type.
MongoDB is Webscale. MySQL is not Webscale, because it uses joins. SQL also has impetus mismatch.
That's actually a rather insightful point...
If your application fits well with the methodologies of a traditional RDBMS, use a traditional RDBMS, and hire people who are trained and experienced in using those methodologies to their full potential.
If you're dealing with the latest Big Data paradigms and designs, where you can sacrifice some of the rigidity of a RDBMS to gain some flexibility and cheaper scalability, use a NoSQL database, and hire people who aren't stuck in their old RDBMS ways.
The real key is for the person doing the hiring to understand which of those of methodologies fits their application.
MySQL is not Webscale, because it uses joins.
Then how does a non-webscale database power popular web sites such as Wikipedia and Slashdot? If you don't do joins in the database, you'll probably end up doing the equivalent of joins (using one value as the key in another table) in your application.
RDBMS systems can be flexible also. It just takes a bit of planning, a good understanding of your data and a well designed application...which you should do/have regardless of your storage solution.
Call me set in my old RDBMS ways, but if I'm supporting it then I want to know what the hell is gong on with the data.
When Fascism comes to America, it will call itself Anti-Fascism, and tell you to give up your guns.
The real key is for the person doing the hiring to understand which of those of methodologies fits their application.
This is insighful. I've worked extensively with RDBMS solutions and now quite a bit with NoSQL technologies. They each have their place. An entire article could be written on where each fits most naturally, but in general if you don't need to join between tables, need to throw data to your store at a high velocity (e.g. logging), and/or need a loose schema, a NoSQL solution works best. If what you're doing can be naturally modeled (i.e. users HAVE AND BELONG TO stations, stations HAVE MANY playlists, etc. etc.), use an RDBMS.
One can see in the subtext of the GP that they may not get this, with their comment that people using RDBMS solutions are "stuck in old ways". It seems like they are saying that NoSQL is effectively always best. I'm curious why they think that. Nail, hammer, etc...
It's better to vote for what you want and not get it than to vote for what you don't want and get it.
- E. Debs
In NoSQL systems such as MongoDB and CouchDB, what do you call the operation where you retrieve one document, pull an identifier out of that document, and use that identifier as the key to retrieve another document?
A CSV or XML or JSON file is a db (a DB is just structured data).
Are relational DBs always required? Certainly not.
The big benefit to a relational DB with lots of enforcement at the data layer is that you can have one or more applications reading/writing to it with minimal concern of data corruption.
What isn't obvious is that second application is often aggregate reporting for management. "How many customers are using $foo and where do they live geographically". With a relational DB, I might knock that query out in a few minutes across millions of customers.
With a flat XML file per customer spread across a number of servers, this could take days to assemble, particularly if $foo is nested deep in the structure.
Having spent far too much time writing one-off scripts to gather customer data because the middleware didn't support that type of query, I've actually gone the other way and started shoving some business logic into the DB.
Functions such as isCustomerPaymentOverdue are now in the relational DB with a very thin model in the middleware to allow for much easier and faster reporting.
Rod Taylor
Or use a better DB like Postgres. How the MySQL still is popular I will never know. I think it is a conspiracy to prove FREE DBs suck.
Urban Airship went PostgreSQL to MongoDB to Cassandra to PostgreSQL. http://wiki.postgresql.org/images/7/7f/Adam-lowry-postgresopen2011.pdf
It's a good presentation because they're in love with none of them and are moving for specific reasons each time, handling different issues. It's not coders chasing the new hotness.
Anyone who loves or hates any language, platform, or manufacturer, doesn't know what they're talking about.
If all your application is ever going to do is read and write to fixed sized record structured data with little relational (or any) attributes then COBOL will suit you fine as that's what it was designed for. Unfortunatly those sorts of apps are few and far between these days, but in its ever decreasing niche COBOL is still good.
Yeah, it really depends on what you are doing. But any time you break normalization there should be a good reason. Performance is certainly a valid reason. "I'm too lazy to make a well-designed database," however, is not.
If you find yourself breaking normalization all the time, then you've probably found a use case where a relational database isn't the best tool for the job.
While there is a "right" way to use a given tool, there is no one tool that is right for every situation. People who get this backwards are zealots and will often make poor decisions.
Check out my world simulator thingy.
The big benefit to a relational DB with lots of enforcement at the data layer is that you can have one or more applications reading/writing to it with minimal concern of data corruption.
Not just that, but good use of relations and normalization makes whole classes of bug impossible.
SJW n. One who posts facts.
In what other language would this statement compile without error:
PERFORM makemoney UNTIL rich.
(Note the the full stop at the end)