25.6.16.22 The ndbinfo dictionary_columns Table

The table provides NDB dictionary information about columns of NDB tables. dictionary_columns has the columns listed here (with brief descriptions):

• table_id

  ID of the table containing the column

• column_id

  The column's unique ID

• name

  Name of the column

• column_type

  Data type of the column from the NDB API; see Column::Type, for possible values

• default_value

  The column's default value, if any

• nullable

  Either of NULL or NOT NULL

• array_type

  The column's internal attribute storage format; one of FIXED, SHORT_VAR, or MEDIUM_VAR; for more information, see Column::ArrayType, in the NDB API documentation

• storage_type

  Type of storage used by the table; either of MEMORY or DISK

• primary_key

  1 if this is a primary key column, otherwise 0

• partition_key

  1 if this is a partitioning key column, otherwise 0

• dynamic

  1 if the column is dynamic, otherwise 0

• auto_inc

  1 if this is an AUTO_INCREMENT column, otherwise 0

You can obtain information about all of the columns in a given table by joining dictionary_columns with the dictionary_tables table, like this:

SELECT dc.*
  FROM dictionary_columns dc
JOIN dictionary_tables dt
  ON dc.table_id=dt.table_id
WHERE dt.table_name='t1'
  AND dt.database_name='mydb';

The dictionary_columns table was added in NDB 8.0.29.

Note

Blob columns are not shown in this table. This is a known issue.