What are the advantages and disadvantages of relational data model and non-relational data model?

Relational database: SQLServer, Oracle, mysql and other features;

① Organizing database with relational model;

2 consistency of transactions;

③ Simply put, the relational model refers to the two-dimensional table model, and the relational database is a data organization composed of two-dimensional tables and their relationships.

Advantages:

Easy to understand: two-dimensional table structure is a concept very close to the logical world, and relational model is easier to understand than other models such as grid and hierarchy;

② Ease of use: The common SQL language makes it very convenient to operate relational databases;

③ Easy to maintain: abundant integrity (entity integrity, referential integrity and user-defined integrity) greatly reduces the probability of data redundancy and data inconsistency;

④ Support SQL, which can be used for complex queries.

Disadvantages:

(1) the huge price paid for consistency is its poor reading and writing performance;

② Fixed table structure;

③ High requirements for concurrent reading and writing;

④ Efficient reading and writing of massive data;

Non-relational database: MongoDb, redis, HBase and other characteristics;

① Use key-value pairs to store data;

② Distributed;

③ Generally, the ACID feature is not supported;

④ Non-relational database is not a database strictly, but a collection of structured data storage methods.

Advantages:

(1) does not need to be parsed by sql layer, so the reading and writing performance is very high;

② Based on key-value pairs, the data is not coupled and easy to expand;

③ Format of storing data: The storage format of nosql is key, value, document, picture, etc. , while relational databases only support basic types.

Disadvantages:

① sql support is not provided, and the cost of learning and using is high;

(2) No transaction processing, poor support for additional functions such as bi and reports;