Relational Database:
MySQL 、Oracle、DB2、Microsoft SQL Server、Microsoft Access
Non-relational databases:
NoSql、redis、Cloudant、MongoDb、HBase
Differences between the two databases:
Relational Database
Characteristics of relational databases
1, a relational database, refers to the use of the relational model to organize the data in the database;
2, the most important feature of the relational database is transactional consistency ;
3, in simple terms, means that the relational model is a two-dimensional form model , and a relational database is organized by a data link between the two-dimensional table and composed.
The advantages of relational database
1, be readily understood : the two-dimensional table structure is very close to a logical world concept, relative to other relational model mesh model, and so it is easier to understand level;
2, easy to use : a common language SQL relational database so that the operation is very convenient;
3, easy to maintain : a wealth of integrity (entity integrity, referential integrity and user-defined integrity) greatly reduce the probability of inconsistent data redundancy and data;
4, support for SQL , can be used for complex queries.
Disadvantage of relational databases
1, in order to maintain consistency pay a huge price is its write performance is poor ;
2, a fixed table structure ;
3, high demand for concurrent read and write ;
4, efficient mass data read and write ;
Non-relational databases
Characteristics of non-relational databases
1, using the key-value pairs stored data;
2, distributed ;
3, generally do not support ACID properties; (Atomicity Atomicity + Consistency Consistency + Isolation Isolation + Persistence Durability Rev)
. 4, strictly non-relational databases is not a database, it should It is a data storage structure for collection methods.
The advantages of non-relational databases
1, without the parsed sql layer, high read performance ;
2, based on a key pair, there is no coupling of data, easy expansion ;
3, the data storage format: nosql storage format is key, value form, the document form, the form of pictures, etc., in the form of documents, pictures, forms, etc., and only supports basic relational database type.
Disadvantage of non-relational databases
1, does not provide support sql , learning and the use of high cost;
2, no transaction processing , additional features such as bi and reporting support is not good;