22.214.171.124 Using PROCEDURE ANALYSE
PROCEDURE ANALYSE() is deprecated as of MySQL 5.7.18, and is removed in MySQL 8.0.
ANALYSE() examines the result from a query and returns an analysis of the results that suggests optimal data types for each column that may help reduce table sizes. To obtain this analysis, append
PROCEDURE ANALYSE to the end of a
SELECT ... FROM ... WHERE ... PROCEDURE ANALYSE([max_elements,[max_memory]])
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_elementsdistinct values, then
ENUMis 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.
PROCEDURE clause is not permitted in a