| Types of | characteristic | advantage | shortcoming |
Relational Database SQLite、Oracle、mysql |
1. A relational database refers to a database that uses a relational model to organize data; 2. The biggest feature of relational databases is the consistency of transactions;3. Simply put, the relational model refers to the two-dimensional table model, and a relational database is composed of two-dimensional tables and the connections between them. data organization. |
1. Easy to understand: The two-dimensional table structure is a concept that is very close to the logical world, and the relational model is easier to understand than other models such as mesh and hierarchy; 2. Easy to use: the general SQL language makes it very convenient to operate relational databases;3. Easy to maintain: rich integrity (entity integrity, referential integrity and user-defined integrity) greatly reduces data redundancy and data inconsistency The probability; 4, support SQL, can be used for complex queries. |
1. The huge price paid for maintaining consistency is that its read and write performance is relatively poor; 2. Fixed table structure;3. High concurrent reading and writing requirements; 4. Efficient reading and writing of massive data; |
non-relational database MongoDb、redis、HBase |
1. Use key-value pairs to store data; 2. Distributed;3. Generally, ACID features are not supported; 4. Non-relational database is not strictly a database, but a collection of data structured storage methods. |
1. There is no need to parse through the sql layer, and the read and write performance is very high; 2. Based on key-value pairs, the data has no coupling and is easy to expand;3. The format of data storage: the storage format of nosql is key, value form, document form, picture form, etc., document form, picture form, etc., while the relationship Type databases only support basic types. |
1. No sql support is provided, and the cost of learning and use is high; 2. There is no transaction processing, and the support for additional functions such as bi and reports is not good; |
注1：数据库事务必须具备ACID特性，ACID是Atomic原子性，Consistency一致性，Isolation隔离性，Durability持久性。
注2：数据的持久存储，尤其是海量数据的持久存储，还是需要一种关系数据库。