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Indexes - Coggle Diagram

- - - - searching for ranges of data
    - - full key value
      - a key range
      - a key prefix
    - - match the full value
      - match a leftmost prefix
      - match a column prefix
      - match a range of values
      - match one part exactly and match a
        range on another part
      - index-only queries
  - - - index the data by all dimensions at the
        same time
    - - MylSAM support spatial indexes
  - - - lookups that use every column in the index
    - - the storage engine computes a hash code
        of the indexed columns
      - probably differ from the hash codes
        computed for other rows with different key values
      - stores the hash codes in the index and
        stores a pointer to each row in a hash table
    - - the default index type for Memory tables
      - the index will store their row pointers in the
        same hash table entry, using a linked list
  - - - Searching for text
    - - Can be created for a text, char, varchar
      - Search are not case sensitive
      - Short words are ignored
    - - MylSAM support spatial indexes
- - - - the <columnList> is a comma-delimited list of columns
        in the table
        
        each column can be specified either in ascending or
        descending order, with ascending being the default