4、 Database design

1、 Denormalization technology

Add redundant columns ： Having the same columns in multiple tables , Used to avoid join operations when querying .

Add derived Columns ： The added columns can be generated by calculating other data in the table . Reduce the amount of calculation when querying , Speed up query .

Reorganize the table ： If many users want to query the result data connected by two tables , Then, the two tables are reorganized into a table to reduce the connection and improve the performance .

Split table ： Splitting tables can improve performance . After horizontal segmentation, the number of data and index pages that need to be read during query can be reduced , At the same time, the number of index layers is reduced , Improve query efficiency . Vertical segmentation can make data rows smaller , One data page can hold more data , Reduce... When querying I/O frequency .

2、 Relational database and non relational database

3、 Memory database and relational database

4、 File systems and relational databases

5、 Cache database

6、 Database high availability technology

Master slave copy ： Avoid single point of failure , Improve query efficiency

Partition ： solve I/O bottleneck , Improve reading and writing efficiency

table ： Resolve concurrency , promote I/O efficiency

sub-treasury ：

cache ：