Introduction to the types of indexes in MySQL

The first thing to understand is that the index is implemented at the storage Engine (storage) level, not at the server level. Not all storage engines support the type of index.

1, B-tree

The most common type of index, his mind is that all values (indexed columns) are ordered, each leaf node is equal to the root node, so it is suitable for finding a range of data, and can directly support the sort (order by) support InnoDB and MyISAM, when indexing multiple columns, The order of the columns is particularly important.

2. Hash index

Based on the hash table, only accurate lookups are supported, range lookups are not supported, and sorting is not supported.

3. Spatial index

4. Full-text Full-text index

It is primarily used to find keywords in text, not directly compared to the values in the index. Can be used in conjunction with B_tree, the two do not conflict. Full-text is used in conjunction with the match against operation and is generally not in the where or like statement.

Introduction to the types of indexes in MySQL