MariaDB CREATE TABLE mysql.column_stats

da https://mariadb.com/kb/en/mariadb/mysqlcolumn_stats-table/

CREATE TABLE mysql.column_stats (
   db_name VARCHAR(64) NOT NULL COMMENT 'Database the table is in.',
   table_name VARCHAR(64) NOT NULL COMMENT 'Table name.',
   column_name VARCHAR(64) NOT NULL COMMENT 'Name of the column.',
   min_value VARCHAR(64) DEFAULT NULL COMMENT 'Minimum value in the table (in text form).',
   max_value VARCHAR(64) DEFAULT NULL COMMENT 'Maximum value in the table (in text form).',
   nulls_ratio DECIMAL(12,4) DEFAULT NULL COMMENT 'Fraction of NULL values (0 - no NULLs, 0.5 - half values are NULLs, 1 - all values are NULLs).',
   avg_length DECIMAL(12,4) DEFAULT NULL COMMENT 'Average length of column value, in bytes. Counted as if one ran SELECT AVG(LENGTH(col)). This doesn\'t count NULL bytes, assumes endspace removal for CHAR(n), etc.',
   avg_frequency DECIMAL(12,4) DEFAULT NULL COMMENT 'Average number of records with the same value',
   hist_size TINYINT(3) UNSIGNED DEFAULT NULL COMMENT 'Histogram size in bytes, from 0-255.',
   hist_type ENUM('SINGLE_PREC_HB', 'DOUBLE_PREC_HB') DEFAULT NULL COMMENT 'Histogram type. ',
   histogram VARBINARY(255),
  PRIMARY KEY (db_name, table_name, column_name)
) ENGINE = InnoDB ROW_FORMAT = DEFAULT;