nosql popularity

1.NOSQL IntroductionNOSQL (not only Sql) refers to a non-relational database. The next generation of databases mainly solves several key points: non-relational, distributed, open-source, horizontally extensible. The original goal was for large-scale Web applications, which began in the early 2009 with features such as freedom of mode, support for simple replication, simple APIs, eventual consistency (non-acid), high-capacity data, and so on.

NoSQL (not-only SQL) non-relational databasecomparison between relational database and non-relational database :Common relational databases: MySQL, Oracle, SQL ServerA relational database involves a federated query (join), which slows down the query when the volume of data is largeNo relationship between NoSQL data, can be expanded arbitrarilyNoSQL data storage is simple, and can exist in memory, so read an

13.4 Scale-out provides performance gainsMany NoSQL systems are based on the key value model, so the query condition is basically based on the key value of the query, there is no time to query the entire data. Since basically all query operations are in the form of basic key values, shards are often also based on data keys: Some properties of the key determine which machine the key value pair is stored on. Below we will describe the hash shard and the

Transferred from:http://blog.jobbole.com/86269/Although hierarchical databases are still widely used on mainframes today, relational database (RDBMS) (SQL) has captured the database market and performed quite well. The money we save doesn't go to someone else's account, and we make sure we have an exclusive seat on the plane, and we're not going to be blamed for what we didn't do, and so on. The data integrity of a relational database is due to its adherence to the principles of acid (atomicity,

as the main data source. Like BerkeleyDB, the license of the product is the same as the GPL. 3, Redis, a typical NoSQL database server, can run on its own server host independently as a service program, compared to BerkeleyDB. In many cases, people just treat Redis as a Key/value database server, but this is not the case, and in the current version (after 2.4 and 2.4), Redis supports list, Hash, set, and sorted in addition to Key/value Set and other

In-depth analysis of distributed algorithms for NoSQL Databases System scalability is the main reason for promoting the development of NoSQL, including distributed system coordination, failover, resource management and many other features. In this case, NoSQL sounds like a big basket, and everything can be inserted. Although the

NoSQL series: Why use NoSQL databases when appropriate databases are selected? The impedance imbalance relationship model does not match the data structure in the memory. More convenient data interaction methods are used to improve development efficiency. The amount of data to be processed is large. The amount of data exceeds the capacity of the relational database. large clusters appear in the cost aspect.

transactions in the database (transaction) have ACID4 basic features that can be compared to trading:1,A (atomicity) atomicityEverything in the transaction is either completed or failed during execution and is rolled back.2,C (consistency) ConsistencyThe database should be in a consistent state.For example: Existing integrity constraints a+b=10, if a transaction changes A, then B must be changed3,I (isolation) IndependenceThe concurrent transactions do not affect each other.If the data to be acc

transactions, but also does not support the associated query , why? Because the associated query requires other nodes to provide data sharding , one query needs to mobilize other nodes, so concurrency performance will be very poor.This kind of lightweight distributed database system, which can only guarantee weak consistency, is a NoSQL system , which removes the correlation.NoSQL is the most used when the number of key-value storage, of course, ther

Although SQL database is a very useful tool, the monopoly is about to be broken after 15 years of a single show. This is only a matter of time: forced to use relational databases, but eventually found to be unable to adapt to the needs of the numerous.But the difference between NoSQL databases is far more than two of the differences between SQL databases. This means that the Software architect should choose a suitable

table, usually according to the user to the table, will be the same user all the data are placed on the same machine, but if we create time to query, want to query all the users in the journal published today, then this will be invalidated. At this point you need to go to each of the sub-table query and then the query results are assembled. And the native SQL is not complete. When an index is unavailable, the aggregation operation is certainly not allowed. SQL or NoSQLSo you can see that SQL is

Guide: Kristóf Kovács is a software architect and consultant who recently published an article comparing various types of NoSQL databases . The article is compiled by Agile translator – Tang Yuhua . For reprint, please refer to the following statement.Although SQL database is a very useful tool, the monopoly is about to be broken after 15 years of a single show. This is only a matter of time: forced to use relational databases, but eventually found to

Recently, the company is making a NoSQL model selection, and has made the following Rough Analysis and Comparison on several common NoSQL databases over a week. Recently, the company is making a NoSQL model selection, and has made the following Rough Analysis and Comparison on several common NoSQL databases over a week

1. Summary Nosql databases are a challenge for traditional SQL databases. Due to the data size expansion of enterprises and Internet applications, SQL cannot support distributed storage and high-speed reading and writing of such massive data, so nosql came into being. Nosql improves database performance through a simple and efficient data storage method such as k

Oracle Releases NoSQL Databases 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, I think of a joke about Sina Weibo's changing weibo.com Domain Name: Three family members made bread, three family me

Recently I am reading nosql. A major advantage of nosql over relational databases is high availability. Therefore, some questions are raised: Why does nosql achieve high availability while relational databases suffer from criticism in this regard? Relational Database Service Oracle and sqlserver are both distributed databases. Definition of distributed

[It168]Nosql was originally abbreviated as not SQL, and has now evolved into not only SQLBecause developers have realized that, in fact, those who prefer SQL and those who have a lot of SQL experience are moreProgramThe cost of employee employment is lower, and such a person is more likely to be recruited. In fact, it is an error that nosql does not use SQL. SQL is not used because of poor performance, bu

Tags: server group data structure POP res cannot object data size user reduceFour types of NoSQL The status of NoSQL database in the whole database field is self-evident. In the era of big data, although the RDBMS is excellent, with the rapid growth of data size and increasingly complex data models, the RDBMS is unable to cope with many database processing tasks, when N