The characteristics of relational database and non-relational database and their advantages and disadvantages

TypeCharacteristicsAdvantagesDisadvantages

relational database

SQLite, Oracle, MySQL

1, relational database, refers to the use of relational model to organize data database;

2, the most important characteristic of relational database is the consistency of transaction;
3, in a nutshell, a relational model is a two-dimensional tabular model, and a relational database is a data organization composed of two-dimensional tables and their linkages.

1, easy to understand: two-dimensional table structure is very close to the logic of the world a concept, the relationship model relative to the network, the level and other models easier to understand;

2, easy to use: The General SQL language makes the operation of relational database very convenient;
3, easy to maintain: rich integrity (Entity integrity, referential integrity and user-defined integrity) greatly reduce the data redundancy and data inconsistency probability;

4, support SQL, can be used for complex queries.

1, in order to maintain the consistency of the huge cost is its poor read and write performance;

2, fixed table structure;
3, high concurrent reading and writing needs;
4. High-efficiency reading and writing of massive data;

Non-relational database

MongoDb, Redis, HBase

1, using key value to store data;

2, distributed;
3, generally do not support acid characteristics;

4, non-relational database is strictly not a database, it should be a data structure of the collection of storage methods.

1, without the SQL layer parsing, read and write performance is very high;

2, based on key-value pairs, the data is not coupled, easy to expand;
3, the format of storing data: NoSQL storage format is key,value form, document form, picture form and so on, document form, picture form and so on, and relational database only support basic type.

1, do not provide SQL support, learning and use of high cost;

2, no transaction processing, additional functions such as BI and report support is not good;

Note 1: Database transactions must have ACID properties, acid is atomic atomic, consistency consistent, isolation isolated, durability persistent.

Note 2: Persistent storage of data, especially persistent storage of massive amounts of data, or the need for a relational database.

The characteristics of relational database and non-relational database and their advantages and disadvantages