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Databases are organized collections of data, most commonly accessed through management systems including schemas, tables, queries and processes that allow users to enter and manipulate the information or utilize it in other fashions, such as with web applications or for reporting purposes.

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Which Database Choose?

This Article about choose the NOSQL database based on application requirement. Different NoSQL DB’s available, there are three primary concerns you must balance when choosing a data management system: consistency, availability, and partition tolerance.

 

* Consistency means that each client always has the same view of the data. * Availability means that all clients can always read and write.

* Partition tolerance means that the system works well across physical network partitions.

 

Chose the Database system based on your application requirement.

 Example Comparing MongoDB and CouchDB.

As you can see in the diagram, MongoDB and CouchDB are built with a slightly different focus. Both scale across multiple nodes easily, but MongoDB favours consistency while CouchDB favours availability.

In the MongoDB replication model, a group of database nodes host the same data set and are defined as a Replica set. One of the nodes in the set will act as primary and the others will be secondary nodes. The primary node is used for all write operations, and by default all read operations as well. This means that replica sets provide strict consistency. Replication is used to provide redundancy - to recover from hardware failure or service interruptions.

CouchDB uses a replication model called Eventual consistency. In this system, clients can write data to one node of the database without waiting for other nodes to come into agreement. The …
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What is SQL Server and how does it work?
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What is SQL Server and how does it work?

The purpose of this paper is to provide you background on SQL Server. It’s your self-study guide for learning fundamentals. It includes both the history of SQL and its technical basics. Concepts and definitions will form the solid foundation of your future DBA expertise.

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Was happy to have a tool like www.newrelic.com. Had an issue where only certain users were experiencing a slow load time. Turned to be code executing too many unnecessary queries that was exposed by looking at long transactions on new relic. Made it a lot easier to find something that otherwise might have taken awhile to narrow down.
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Is it just me or is NoSQL Overapplied? It seems like in an effort to be as trendy as possible people shoehorn obviously relational problems into non relational schema. If you have to start throwing foreign keys on your objects I think you need to rethink your solution. Sarah Mei makes a good point about this in her article:

http://www.sarahmei.com/blog/2013/11/11/why-you-should-never-use-mongodb/
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Expert Comment

by:Phil Phillips
It was definitely over applied initially. Though, I think it's gotten better over the years. Part of it, too, is that a lot of the relational databases started incorporating NoSQL-like features (i.e. PostgreSQL and their JSON capabilities).
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Databases

54K

Solutions

75

Articles & Videos

38K

Contributors

Databases are organized collections of data, most commonly accessed through management systems including schemas, tables, queries and processes that allow users to enter and manipulate the information or utilize it in other fashions, such as with web applications or for reporting purposes.