Syntax
------

analyse([max_elements[,max_memory]])

Description
-----------

This procedure is defined in the sql/sql_analyse.cc file. It examines the
result from a query and returns an analysis of the results that suggests
optimal data types for each column. To obtain this analysis, append PROCEDURE
ANALYSE to the end of a SELECT statement:

SELECT ... FROM ... WHERE ... PROCEDURE ANALYSE([max_elements,[max_memory]])

For example:

SELECT col1, col2 FROM table1 PROCEDURE ANALYSE(10, 2000);

The results show some statistics for the values returned by the query, and
propose an optimal data type for the columns. This can be helpful for checking
your existing tables, or after importing new data. You may need to try
different settings for the arguments so that PROCEDURE ANALYSE() does not
suggest the ENUM data type when it is not appropriate.

The arguments are optional and are used as follows:

* max_elements (default 256) is the maximum number of distinct values that
analyse notices per column. This is used by analyse to check whether the
optimal data type should be of type ENUM; if there are more than max_elements
distinct values, then ENUM is not a suggested type.
* max_memory (default 8192) is the maximum amount of memory that analyse
should allocate per column while trying to find all distinct values.

URL: https://mariadb.com/kb/en/procedure-analyse/