Defining MySQL Table Indexes

The following properties are applicable to a MySQL table index.

Tab

Property

Description

Additional Information

Members Column

Specifies the columns that are included in the index

Specifies the expressions for multivalued indexes

 
Length Specifies the prefix length of the column  
Sort Order Specifies the order in which index values are stored  
Column/ Expression Specifies the cast expression for a multivalued index Available for only multivalued indexes
Options Category Specifies the index category

Fulltext: Indicates that the indexing happens over the entire column

Spatial: Indicates that the indexing happens over the spatial columns

 

Algorithm Specifies the algorithm used to perform table copying operations

Default: Indicates that the operations only modify metadata in the data dictionary

Inplace: Indicates that the operations do not copy table data but may rebuild the table

Copy: Indicates that the operations are performed on a copy of original table

Type Specifies the index type to be used  
Lock option Specifies the concurrency level for reading and writing table

Default: Indicates the maximum level of concurrency for a given algorithm

None:Indicates that concurrent reads and writes are permitted

Shared: Indicates that concurrent reads are permitted but not concurrent writes

Exclusive: Indicates that exclusive access is enforced

Parser Name Specifies the fulltext parser name Available for only fulltext indexes
Key Block Size Specifies the size (in bytes) of index key blocks in the storage engine Available for MyISAM tables
Visibility Specifies the index visibility

Visible: Indicates that the index is used by the optimizer

Invisible: Indicates that the index is not used by the optimizer