top 10 nosql databases

NoSQL database: Consistent read consistency for data Strong consistencyWhen visiting any node in the cluster at any time, the data results are consistent; User consistencyFor the same user, access to the data obtained during the cluster is consistent;Resolve user consistency: Use sticky sessions to bind sessions to specific nodes for processing;This will reduce the performance of the load balancer; Finally consistentThe data synchroni

Oracle, as the world's largest relational Database provider, has also joined the NoSQL Database chain in its product chain. In addition, this new Database name is so domineering that it is called NoSQL Database. Oracle's NoSQL Database is one of the components of the Big Data Appliance released on Oracle's global Daquan in October 4, big Data Appliance is a syst

PHP operations on MongoDB [NoSQL] databases. if you need them, refer to MongoDB. I. MongoDB introduction MongoDB (named from "humongous") is a scalable, high-performance, open-source, free-mode, document-oriented database, it combines the advantages of document databases, key-value pairs, and relational databases. Of

For PHP operations on MongoDB [NoSQL] databases, refer to section 1. MongoDB introduction. MongoDB (named from "humongous") is a scalable, high-performance, open-source, free-mode, document-oriented database, it combines the advantages of document databases, key-value pairs, and relational databases. Official site: ht

Write efficiency is very high. To achieve data persistence, Redis supports regular refresh (which can be implemented through configuration) or log writing to save data to the disk. Installation and Use Because there is no third-party package dependency, Redis installation is very simple: $ Wget http://redis.googlecode.com/files/redis-2.2.11.tar.gz $ Tar xzf redis-2.2.11.tar.gz $ Redis-2.2.11 cd $ Make After the installation is complete, execute the redis-server under the src directory to start

number of fragmented files,theCPU can first throw this heap of files into a faster cache, and then the CPU You can do other things first. The hard disk then writes this heap of fragmented small files from the cache to the hard disk surface. Hard disk caching helps to improve the performance of hard disk's burst read-write and random read/write. Good , before we get back to our point of , Why does it appear NoSQL Database example : record the clic

function relative limitation 3. Document-based database Examples CouchDB, MongoDb Typical application Scenarios Web applications (similar to Key-value, value is structured, but the database is able to understand the contents of value) Data model Key-value corresponding key-value pairs, value is structured data Strengths Data structure requirements are not strict, table structure is variable, do not need to

Random access performance comparable to MySQL Best practice scenario: for Preference BigTable:) and for random, real-time access to big data.For example: Facebook message database (more common use cases are about to appear)Note 4:thrift is an interface definition language that provides definition and creation services for a variety of other languages, developed by Facebook and open source.Of course, all systems do not only have these features listed above. Here I just list some of the

two versions are reserved for application layer processing.This problem is common in scenarios such as data consistency maintenance and cluster State synchronization, such as cluster member information propagation. While a coordinator who introduces a monitoring database and develops a synchronization plan can solve this problem, a centralized database can provide better fault tolerance. The main practice of de-centering is to use a well-designed infection protocol [7], which is relatively simp

Tags: nosqlNoSQL databases: Consistency of dataRead consistency Strong consistencyAccess to any node in the cluster at any time, resulting in consistent data results; User consistency for the same user, access to the data during the cluster is consistent;Resolve user consistency: Use sticky sessions to bind sessions to specific nodes for processing;This reduces the performance of the load balancer; Final consistencyThe data synchroniz

Source: comparison of various nosql databases in http://hi.baidu.com/eastdoor/blog/item/758d0e3eedb5d92471cf6c14.html Cassandra, MongoDB, CouchDB, Redis, Riak, HBaseCouchDBDevelopment language: ErlangMain advantages: data consistency and ease of useLicense: ApacheProtocol: HTTP/RESTApplicable: accumulated, less changed data. Or a large number of versions are required.Example: CRM, CMS systems. multi-site de

1. MongoDB Introduction MongoDB is a distributed file storage-based database. Written in C ++. It mainly solves the access efficiency of massive data and provides scalable and high-performance data storage solutions for Web applications. When the data volume exceeds 50 GB, The MongoDB database access speed is more than 10 times that of MySQL. MongoDB's concurrent read/write efficiency is not particularly good. According to the official performance tes

Tags: style http color ar os using strong file dataOriginal address: http://database.51cto.com/art/201109/291781.htm In the current enterprise IT architecture, system administrators and DBAs will consider using NoSQL databases to solve problems that RDBMS cannot solve, especially in the internet industry. Traditional relational databases store data in the form of

ObjectiveNosql:not only SQL (not no SQL), it means using a relational database when the relational database is applied, but using a different database where it is not suitable for a relational database. The emergence of NoSQL is mainly to make up for the deficiency of relational database, it can be regarded as a supplement of relational database. It must be understood, however, that NoSQL is not meant to re

operations, so very slow, and the associated query is also very complex, resulting in low efficiency, often query business does not go index, query speed is very slow, mainly because of the complexity of the performance of the lower Summary Choosing a nosql requires the following 2 prerequisites:1. No acid required2. No correlation query required If you need the above two functions, you cannot select NoSQL

original data set to improve query efficiency. Shortcomings are also more obvious, updating the reviewer data will be more troublesome.(4) Data coupling?: SQL does not allow the deletion of external data that has already been used, such as "Bear three" in the reviewer table has been assigned to the borrower bear big, then in the reviewer table will not be allowed to delete the bear three this data to ensure data integrity, and NoSQL there is no such

can also be detected based on patterns between relationships (fraud in transaction).non-applicable occasionsThe graph database may not be applicable in some cases. This is the case when updating an entity in all or a subset. For example, in a "Data analysis solution" (analytics solution), all entities have to be updated as soon as one attribute is changed. The effect of the graph database is not ideal, because the simple operation can change a property in all nodes at once. Even if the data mod

The relational database management system still occupies the position of the industry leading. But even if you are a complete Oracle powder, deeply attracted to the pl/sql architecture of the old RAC, keep your mind and stay calm. Times are different, and now we need to think carefully before embarking on a task, and we must never choose a solution on the basis of personal likes and dislikes. This article lists 10 things that you must avoid when you u

QT provides a qtsql module to provide platform-independent SQL-based database operations. What we call "platform independence" here includes both the operating system platform and the various database platforms. In addition, we emphasize "SQL-based" because NoSQL databases do not have a common query method so far, so it is impossible to provide a generic NoSQL da

:Select * from Xinxi where name= ' John Doe ' and nianling=2610, or ... "or"Select * from Xinxi where name= ' John Doe ' or nianling=2611, IN (...) In... Range ofColumn names are queried for which range to query.Select * from Xinxi where nianling in (21,22,23,24)Select * from Xinxi where name in (' John Doe ', ' Zhao Liu ')12, not...in (...) Not... Range ofSelect * from Xinxi where name is not in (' John Doe ', ' Zhao Liu ')13, wildcard% means any number of any character; Like, fuzzy query, when