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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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When should I use a NoSQL database instead of a relational database? Is it okay to use both on the same site?

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.
smfoote
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What does "Document-oriented" vs. Key-Value mean when talking about MongoDB vs Cassandra?

What does going with a document based NoSQL option buy you over a KV store, and vice-versa?
tesserakt
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NoSql vs Relational database

Recently NoSQL has gained immense popularity. What are the advantages of NoSQL over traditional RDBMS?
user496949
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Where does mongodb stand in the CAP theorem?

Everywhere I look, I see that MongoDB is CP. But when I dig in I see it is eventually consistent. Is it CP when you use safe=true? If so, does that mean that when I write with safe=true, all replicas will be updated before getting the result?
Gluz
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NoSQL - MongoDB vs CouchDB

I am a complete noob when it comes to the NoSQL movement. I have heard lots about MongoDB and CouchDB. I know there are differences between the two. Which do you recommend learning as a first step into the NoSQL world?
mpenrow
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What is the recommended way to delete a large number of items from DynamoDB?

I'm writing a simple logging service in DynamoDB. I have a logs table that is keyed by a user_id hash and a timestamp (Unix epoch int) range. When a user of the service terminates their account, I need to delete all items in the table, regardless of…
Tyler
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Difference between HBase and Hadoop/HDFS

This is kind of naive question but I am new to NoSQL paradigm and don't know much about it. So if somebody can help me clearly understand difference between the HBase and Hadoop or if give some pointers which might help me understand the…
Dhaval Shah
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What is an SSTable?

In BigTable/GFS and Cassandra terminology, what is the definition of a SSTable?
knorv
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Use cases for NoSQL

NoSQL has been getting a lot of attention in our 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…
robjmills
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What does Redis do when it runs out of memory?

This might be easy question but I am having a hard time finding the answer. How does Redis 2.0 handle running out of maximum allocated memory? How does it decide which data to remove or which data to keep in memory?
Cory
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How do you track record relations in NoSQL?

I am trying to figure out the equivalent of foreign keys and indexes in NoSQL KVP or Document databases. Since there are no pivotal tables (to add keys marking a relation between two objects) I am really stumped as to how you would be able to…
Xeoncross
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Foreign keys in mongo?

How do I design a scheme such this in MongoDB? I think there are no foreign keys!
Mark Pegasov
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Good reasons NOT to use a relational database?

Can you please point to alternative data storage tools and give good reasons to use them instead of good-old relational databases? In my opinion, most applications rarely use the full power of SQL--it would be interesting to see how to build an…
caustic
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SQL (MySQL) vs NoSQL (CouchDB)

I am in the middle of designing a highly-scalable application which must store a lot of data. Just for example it will store lots about users and then things like a lot of their messages, comments etc. I have always used MySQL before but now I am…
christophmccann
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How Can I Browse/View The Values Stored in Redis

Are there any good browsers/explorer for viewing Redis out there ? Am new to Redis so my expectation is if there is something similar to MongoVUE,Toad or SQLExplorer. I tried Redis Admin UI from service stack but ran into 500 error when trying on…
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