DESC[RIBE]

Purpose

Use this statement to print column information for a given table or view.

Prerequisites

  • If the object to be described is a table, one of the following conditions must be fulfilled:
    • The current user has one of the following system privileges: SELECT ANY TABLE (or SELECT ANY DICTIONARY in context of system tables, respectively),INSERT ANY TABLE, UPDATE ANY TABLE, DELETE ANY TABLE, ALTER ANY TABLE or DROP ANY TABLE.
    • The current user has any object privilege on the table.
    • The table belongs to the current user or one of his roles.
  • If the object to be described is a view, one of the following conditions must be fulfilled:
    • The current user has one of the following system privileges: SELECT ANY TABLE or DROP ANY VIEW.
    • The current user has any object privilege on the view.
    • The view belongs to the current user or one of his roles.

Syntax

describe::=

Describe statement

Usage Notes

  • The SQL_TYPE column displays the datatype. In case of a string type, the used character set will be additionally shown (ASCII or UTF-8).
  • The NULLABLE column indicates whether the column is permitted to contain NULL values.
  • The value of columns DISTRIBUTION_KEY and PARTITION_KEY show whether the column is part of the distribution and partition keys (for additional information, see ALTER TABLE (distribution/partitioning)). For Views these values are always NULL.
  • If you specify the option FULL, then the additional column COLUMN_COMMENT displays the column comment (cut to maximum 200 characters), if this was set either implicitly by the CREATE TABLE or CREATE VIEW command or explicitly by the COMMENT statement.
  • DESCRIBE can be abbreviated by DESC (for example, DESC my_table;).

Example

CREATE TABLE t (i DECIMAL COMMENT IS 'id column',
         d DECIMAL(20,5),
         j DATE,
         k VARCHAR(5),
         DISTRIBUTE BY i,
         PARTITION BY d);
DESCRIBE t;

Example Result

COLUMN_NAME SQL_TYPE NULLABLE DISTRIBUTION_KEY PARTITION_KEY
I DECIMAL(18,0) TRUE TRUE FALSE
D DECIMAL(20,5) TRUE FALSE TRUE
J DATE TRUE FALSE FALSE
K VARCHAR(5) UTF- TRUE FALSE FALSE