mongodb

Random record from MongoDB

I am looking to get a random record from a huge (100 million record) mongodb. What is the fastest and most efficient way to do so? The data is already there and there are no field in which I can generate a random number and obtain a random row. Any suggestions? ...

Rails and MongoDB with MongoMapper

I'm new to Rails development and I'm starting with MongoDB also. I have been following this Railscast tutorial about complex forms with Rails but I'm using MongoDB as my database. I'm having no problems inserting documents with it's childs and retrieving the data to the edit form, but when I try to update it I get this error undefi...

What database systems should an startup company consider?

Right now I'm developing the prototype of a web application that aggregates large number of text entries from a large number of users. This data must be frequently displayed back and often updated. At the moment I store the content inside a MySQL database and use NHibernate ORM layer to interact with the DB. I've got a table defined for ...

'schema' design for a social network

I'm working on a proof of concept app for a twitter style social network with about 500k users. I'm unsure of how best to design the 'schema' should I embed a user's subscriptions or have a separate 'subscriptions' collection and use db references? If I embed, I still have to perform a query to get all of a user's followers. e.g. Giv...

How to store UTC time values in Mongo with Mongoid?

The behavior I'm observing with the Mongoid adapter is that it'll save 'time' fields with the current system timezone into the database. Note that it's the system time and not Rail's environment's Time.zone. If I change the system timezone, then subsequent saves will pick up the current system timezone. # system currently at UTC -7 @r...

MongoDB based messaging application?

Is there any application ( not Facebook or Twitter, but something I can install and deploy locally) that provides personal messaging using MongoDB or any such document oriented DB? ...

How to combine conditional operator in NoRM driver for MongoDB

Hi guys In mongo native api it is possible to do following: db.collection.find({ "field" : { $gt: value1, $lt: value2 } } ); // value1 < field < value How could I achieve the same with NoRM Best regards, Dmitry Egorov ...

php mongodb findOne return as object?

is it possible to return findOne result as object ..or it always return an array? i found something about mongo.objects = 1 adding to php.ini ..but did not work for me. can some one tell me more about this? ...

Are document-oriented databases meant to replace relational databases?

Recently I've been working a little with MongoDB and I have to say I really like it. However it is a completely different type of database then I am used. I've noticed that it is most definitely better for certain types of data, however for heavily normalized databases it might not be the best choice. It appears to me however that it ...

How to query through a DBRef in MongoDB/pymongo?

Is it possible to query through a DBRef using a single find spec? user collection { 'age': 30 } post collection { 'user': DBRef('user', ...) } Is it possible to query for all post who's users are 30 in a single find step? If not, would it be wise to create a javascript function to handle the multi-stage operation or will ...

Which is the best java driver for mongodb access?

I have no experience with MongoDB and we are trying to port a JPA application to be based on MongoDB. There are 3 drivers mentioned for porting java here. Which driver would be the easiest to use for converting my existing JPA application? Would it be morphia, mungbean or daybreak. Would prefer some practical experiences with users who h...

Web Shop Schema - Document Db

I'd like to evaluate a document db, probably mongo db in an ASP.Net MVC web shop. A little reasoning at the beginning: There are about 2 million products. The product model would be pretty bad for rdbms as there'd be many different kinds of products with unique attributes. For example, there'd be books which have isbn, authors, titl...

Use cases for NoSQL

NoSQL has been getting a lot of attention in the industry recently. I'm really interested in what peoples thoughts are on the best use-cases for its use over relational database storage. What should trigger a developer into thinking that particular datasets are more suited to a NoSQL solution. I'm particularly interested in MongoDB and C...

Perform case-insensitive lookup on an Array in MongoDB?

So, I've decided to get my feet wet with MongoDB and love it so far. It seems very fast and flexible which is great. But, I'm still going through the initial learning curve and as such, I'm spending hours digging for info on the most basic things. I've search throughout the MongoDB online documentation and have spent hours Googling th...

how to have separate keys per record in mongo_mapper + Rails

When I'm adding a record in mongodb I can specify whatever keys I want and it will store it in the db. The problem is that it will remember those keys for the next time I insert another record. so for example if I do the following: Product.create :foo => 123 and then Product.create :bar => 456 I get :foo => nil field in the 2nd rec...

What db fits me?

Dear Everyone I am currently using mysql. I am finding that my schema is getting incredibly complicated. I seek to find a new db that will suit my needs: Let's assume I am building a news aggregrator (which collects news from multiple website). I then run algorithms to determine if two news from different sites are actually referring to...

Is there a better alternative to the Mongo shell?

Dear Everyone, Is there a better shell than the native mongo shell? When I press UP I am seeing ^[[A . Does the shell not support last query? Tabbing in the shell does not autocomplete either. Of course, if there's a shell with syntax highlighting that would be great Is there an alternative that has the following features? (Or ...

how to test if a string is a valid UTF16 string?

I am using mongodb and javascript to do some string processing. Now I got some error like: Sun May 23 07:42:20 Assertion failure JS_EncodeCharacters( _context , s , srclen , dst , &len) scripting/engine_spidermonkey.cpp 152 0x80f4f7e 0x80f8794 0x811525b 0x811a953 0x8119fc4 0x8111bc5 0x81b408e 0x81c4ee7 0x81b4a10 0x817a881 0x817a7...

Wrapping my head around MongoDB, mongomapper and joins...

I'm new to MongoDB and I've used RDBMS for years. Anyway, let's say I have the following collections: Realtors many :bookmarks key :name Houses key :address, String key :bathrooms, Integer Properties key :address, String key :landtype, String Bookmark key :notes I want a Realtor to be able to bookmark a House and/or a ...

Mongodb vs. Cassandra

I am evaluating what might be the best migration option. Currently, i am on a sharded mysql (horizontal partition), with most of my data stored in json blobs. I do not have any complex SQL queries( already migrated away after since I partitioned my db) Right now, it seems like both Mongodb and Cassandra would be likely options. My situ...