Well, NoSQL is a buzzword right now so I've been looking into it. I'm yet to get my head around ColumnFamilies and SuperColumns, etc... But I have been looking at how the data is mapped. After reading this article, and others, it seems the data is mapped in a JSON like format. Users = { 1: { username: "dave", passwo...
I'm trying to convert a django project for GAE, and I've stumbled upon this: (relational-databse) class Clan(models.Model): wars = models.ManyToManyField('self') How can I do this in a non-relational database(i.e. gae datastore)? ...
Simple question, could I conceivably use redis instead of mysql for all sorts of web applications: social networks, geo-location services etc? ...
Given a simple json document such as: { _id: 1234, messages: [...], otherfields: ... } If two people open the document, and push a message onto the array, the first update will be clobbered by the second. For types other than arrays, I'm ok with this. In an rdbms this isn't an issue since the two messages are simply inserted into ...
Hi everybody, I am thinking about using a noSQL (mongoDB) paired with memcached to store sessions with in my webapp. The idea is that upon each page load, the user data is compared to the data in the memcache and if something has changed, the data would be written to both memcached and mySQL. This way the reads would be greatly reduced ...
whats difference between NoSql DB and OO Db? ...
If You would be Facebook, what nosql db would you use and to do what? I mean the real use cases where a NOSQL makes really an advantage ...
I'm new to databases, but I think I finally have a situation where flat files won't work. I'm writing a program to analyze the outcomes of multiplayer games, where each game could have any number of players grouped into any number of teams. I want to allow players can win, tie, or leave partway through the game (and win/lose based on te...
I have a query which looks like this: Possesion.objects.exclude(~Q(type="money") & ~Q(type="people")) I want the possessions which are of any type other than "money" and "people". Is there any easier way to do this without something like queried_possesions = POSSESION_TYPES queried_possesions.remove("money") queried_possesions.remo...
There are products with a name and price. Users log about products they have bought. # option 1: embed logs product = { id, name, price } user = { id, name, logs : [{ product_id_1, quantity, datetime, comment }, { product_id_2, quantity, datetime, comment }, ... , {...
What are the advantages of using NoSQL databases? I've read a lot about them lately, but I'm still unsure why I would want to implement one, and under what circumstances I would want to use one. ...
This post says that you need a 64 bit system for MongoDB if your data is bigger than 2GB. In my local machine, a 64 bit Intel C2D running 32 bit Mac OS X Leopard, the MongoDB 64 bit version runs without any error. On the server, a 64 bit machine running 32 bit CentOS 5.0, the 64 bit MongoDB won't run. 32 bit runs OK. My question is, d...
Links have one or more tags, so at first it might seem natural to embed the tags: link = { title: 'How would you implement these queries efficiently in MongoDB?' url: 'http://stackoverflow.com/questions/3720972' tags: ['ruby', 'mongodb', 'database-schema', 'database-design', 'nosql']} How would these queries be imple...
I'm implementing a chat system. What kind of database I should use for logging chat messages? I need to do some queries to it. For example "give me all the links from user x between these dates" I've heard some good things about MongoDB for this kind of stuff. How about other NoSQL solutions? Redis? Cassandra? How about old SQL solut...
There was an article on Hacker News a couple of days ago that reached first page titled something like "2 cases when not to use Mongodb" but I really can't find it anymore... Does anyone know where I can find the above described article? What cases are there when NoSQL fails? ...
Hi all, Would it be a good option to use key-value store database like cassandra and riak for storing your texts, which will be used for full-text search? If it is not recommendable, what are the reason for not going this path? Anybody has any experience on using key-value store for full-text search store? Thanks for sharing. ...
I'm new to CouchDB and want to give it a try. But before I do that I want to know if I can create dynamic database structure in CouchDB. Eg. The user starts on a blank thread and chooses whatever structure he/she wants (eg. title, body and tags and fill them in) When he clicks save thread the database for this is created, maybe nested...
I need graph database for my project. I want to perform shortest path operation on the graph. I searched google and found neo4j, InfoGrid and sones. I am not sure which one performs the best. Neo4j is insisting on transaction for read queries also, so I am worried it will cause delays. I want high performance graph database engine. It w...
Hi, What is the pros and cons of MongoDB (document-based), HBase (column-based) and Neo4j (objects graph)? I'm particularly interested to know some of the typical use cases for each one. http://stackoverflow.com/questions/703999/what-are-some-examples-of-problems-that-are-best-solved-with-graphs Maybe any Slideshare or Scribd...
So I have done some research and found out that MongoDB doesn't do fsync(), which means that when you tell the database to write something, the database might tell you it's written, although it's not. Isn't this going against CRUD? If I'm correct, are there any good reasons for this? ...