INFORMATION_SCHEMA

-- Spalten suchen
SELECT table_schema, table_name, column_name, ordinal_position, data_type, character_maximum_length, numeric_precision, numeric_scale, column_type
  FROM information_schema.columns
  WHERE LOWER(column_name) LIKE '%%'
  ORDER BY table_schema, table_name, column_name
;

-- Überhang
SELECT table_schema, table_name, engine, table_rows, avg_row_length, data_length, max_data_length, index_length, data_free
  FROM information_schema.tables
  WHERE data_free > 0
  ORDER BY data_free DESC
;

-- Indizes
SELECT
       table_schema, table_name, non_unique, index_name, seq_in_index, column_name, cardinality, nullable
  FROM information_schema.statistics
  WHERE
         lower(table_schema) LIKE 'bdb%'
     AND lower(table_name)   LIKE '%'
     AND lower(index_name)   LIKE '%'
  ORDER BY table_schema, table_name, index_name, seq_in_index
;

--  Fremdschlüssel

SELECT
        table_schema
      , table_name
      , constraint_name
      , column_name
      , referenced_table_name
      , referenced_column_name
  FROM
      information_schema.key_column_usage
  WHERE
          referenced_table_name IS NOT NULL
  ORDER BY
        table_schema
      , table_name
      , constraint_name
      , column_name
      , referenced_table_name
      , referenced_column_name
;

-- 

USE 'mydb'

SELECT
    CONCAT(table_name, '.', column_name)                       AS 'foreign key',
    CONCAT(referenced_table_name, '.', referenced_column_name) AS 'references',
    constraint_name                                            AS 'constraint name'
  FROM
      information_schema.key_column_usage
  WHERE
          referenced_table_name IS NOT NULL
      AND table_schema = DATABASE()
  ORDER BY table_name, column_name, referenced_table_name,  referenced_column_name
;

SELECT tc.table_name, tc.constraint_type, tc.constraint_name, kcu.referenced_table_name, kcu.referenced_column_name
  FROM information_schema.table_constraints tc LEFT JOIN information_schema.key_column_usage kcu ON tc.constraint_name = kcu.constraint_name
  WHERE tc.constraint_type = 'FOREIGN KEY'
    AND tc.table_schema = DATABASE()
  ORDER BY tc.table_name, kcu.referenced_table_name
;

-- Storage Engines
SELECT table_schema, table_name, table_type, engine, version, row_format, table_rows, avg_row_length, data_length, index_length
  FROM information_schema.tables
  WHERE  table_schema = DATABASE()
  ORDER BY Engine, table_schema, table_name
;