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Questions tagged [nosql]

NoSQL (sometimes expanded to "not only SQL") is a broad class of database management systems that differ from the classic model of the relational database management system (RDBMS) in some significant ways.

NoSQL (sometimes expanded to "not only ") is a broad class of database management systems that differ from the classic model of the relational database management system () in some significant ways.

NoSQL systems:

  • Specifically designed for high load
  • Natively support horizontal scalability
  • Fault-tolerant
  • Store data in a denormalized manner
  • Do not usually enforce strict database schema
  • Do not usually store data in a table
  • Sometimes provide eventual consistency instead of ACID transactions

In contrast to RDBMS, NoSQL systems:

  • Do not guarantee data consistency
  • Usually support a limited query language (a subset of SQL or another custom query language)
  • May not provide support for transactions/distributed transactions
  • Do not usually use some advanced concepts of RDBMS, such as triggers, views, stored procedures

NoSQL implementations can be categorized by their manner of implementation:

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13110 questions
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large amount of inserts per seconds causing massive CPU load

I have a PHP script that in every run, inserts a new row to a Mysql db (with a relative small amount of data..) I have more than 20 requests per second, and this is causing my CPU to scream for help.. I'm using the sql INSERT DELAYED method with a…
jsbuster
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Distributed store with transactions

I currently develop an application hosted at google app engine. However, gae has many disadvantages: it's expensive and is very hard to debug since we can't attach to real instances. I am considering changing the gae to an open source alternative.…
Konstantin Solomatov
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Polyglot persistence example

I want to store my data on both SQL databases and NoSQL databases. This scenario can be described as Polyglot Persistence. Is there any code sample which implements Polyglot Persistence. If you don't know Polyglot Persistence please read this link
prnawa
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DynamoDB: Get All Items

I'm trying to retrieve all of the keys from a DynamoDB table in an optimized way. There are millions of keys. In Cassandra I would probably create a single row with a column for every key which would eliminate to do a full table scan. DynamoDBs…
Nick
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Best data model for massive relationships in MongoDB

We're adopting MongoDB for a new solution and are currently trying to design the most effective data model for our needs are regards relationships between data items. We've got to hold a three way relationship between users, items and lists. A user…
Bob Tway
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RavenDb Index sorting

Let's imagine we have the simplest Map index: Map = posts => from post in posts orderby post.DateTime select new { Id = post.Id, DateTime = post.DateTime } How does OrderBy clause will influence on Map index results?…
SiberianGuy
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Amazon DynamoDB - Scale and benefits, but is it a right fit

I've got an application that I've built that, if all goes well could generate a large amount of data. At present I'm using a MySQL database to store the information and I make use of INNER and LEFT joins on queries to filter data. Now I was going to…
TommyBs
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RavenDb Return only indexed fields

Let's imagine I have the following index: public class PostsForList: AbstractIndexCreationTask { public class ReduceResult { public string Id { get; set; } public string Title { get; set; } public…
SiberianGuy
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Backing up Riak Data when changing backends

I have Riak (1.0.2) installed in my VMWare Workstation running Ubuntu Linux Natty. It's a single machine installation and not a cluster. I changed my backend from BitCask to LevelDB to take advantage of secondary indices. However, now all my other…
ObiHill
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Is there a way to log queries on Neo4J like Hibernate?

So, here is the scenario: I have Neo4J server running locally with some data in it I have a web app using spring-data-neo4j The following code is based on the example code Cineasts: public interface CrewRepository extends GraphRepository { …
Tarcio Saraiva
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Does Redis / Memcached / MongoDB (or any NoSQL systems) support MySQL's ON DUPLICATE KEY UPDATE?

I need to keep track of which user has visited which page how many times. In MySQL I'd do something like this: INSERT INTO stats (user_id, url, hits) VALUES (1234, "/page/1234567890", 1) ON DUPLICATE KEY UPDATE hits = hits + 1; In the table stats…
Continuation
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RavenDB inner collection paging

I am new to RavenDB and from my understanding, when you ask for the document, you will get the entire document (unless you use some sort of index, etc). Example Scenario Take for example the Blog document scenario, where the document looks like…
Adam Spicer
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What is a graph database?

Looking at options for an embedded NoSQL database written in Java, graph databases come up. What is a graph database (especially in contrast to a key-value store and a document-oriented database) and when would I use one (and when not)?
Thilo
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mongoose error when use push()

-- express_example |---- app.js |---- models |-------- songs.js |-------- albums.js |---- and another files of expressjs songs.js: var mongoose = require('mongoose'), Schema = mongoose.Schema, ObjectId = Schema.ObjectId; var…
Huy Tran
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Specify index document collection sorting

Let's imagine I have the following index definition: public class LastSuspensions: AbstractIndexCreationTask { public class ReduceResult { public string CityId { get; set; } …
SiberianGuy
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