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What are the types of MySQL indexes?

2022-02-04 16:52:17 Alibaba cloud Q & A

MySQL What are the types of indexes ?




Take the answer 1:

primary key : Duplicate columns are not allowed , It is not allowed to be NULL, A table can only have one primary key .

unique index : Duplicate columns are not allowed , Allow for NULL value , A table allows multiple columns to create unique indexes .

General index : Basic index types , There is no limit to uniqueness , Allow for NULL value .

Full-text index : Is the current search engine use of a key technology , Segmentation of the content of the text 、 Search for .

Overlay index : The query column should be covered by the index , You don't have to read rows of data

Composite index : Multiple column values form an index , For combined search , Efficiency is greater than index merging


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