Find db.table.columns that are > 90% auto_increment capacity

max_auto_increment_tables.sql

SELECT TABLE_SCHEMA, TABLE_NAME, COLUMN_NAME, COLUMN_TYPE,
  (CASE DATA_TYPE
      WHEN 'tinyint' THEN 255
      WHEN 'smallint' THEN 65535
      WHEN 'mediumint' THEN 16777215
      WHEN 'int' THEN 4294967295
      WHEN 'bigint' THEN 18446744073709551615
   	END >> IF(LOCATE('unsigned', COLUMN_TYPE) > 0, 0, 1)
  ) AS MAX_VALUE,
  AUTO_INCREMENT AS CURRENT_VALUE,
  ROUND((AUTO_INCREMENT /
  (CASE DATA_TYPE
      WHEN 'tinyint' THEN 255
      WHEN 'smallint' THEN 65535
      WHEN 'mediumint' THEN 16777215
      WHEN 'int' THEN 4294967295
      WHEN 'bigint' THEN 18446744073709551615
      END >> IF(LOCATE('unsigned', COLUMN_TYPE) > 0, 0, 1)
  ))*100, 2) AS AUTO_INCREMENT_RATIO
FROM
  INFORMATION_SCHEMA.COLUMNS INNER JOIN INFORMATION_SCHEMA.TABLES USING (TABLE_SCHEMA, TABLE_NAME)
WHERE
  TABLE_SCHEMA NOT IN ('mysql', 'INFORMATION_SCHEMA', 'performance_schema') AND EXTRA = 'auto_increment'
HAVING AUTO_INCREMENT_RATIO > 90;