DESCRIBE

Purpose

Use the DESCRIBE command to list the column definitions of a table or view.

This command provides the functionality of the SQL*Plus DESCRIBE command within RMAN.

Prerequisites

To access a table or view in another schema, you must have READ or SELECT privileges on the object or connect in AS SYSDBA mode. The SYSBACKUP privilege does not grant access to user tables or views.

Usage Notes

Descriptions provide this information for each column in the table or view:

  • Name

  • Whether null values are permitted (NULL or NOT NULL)

  • Data type and, where applicable, the precision or scale

Semantics

Syntax Element Description

CATALOG

Identifies the object as residing in the database containing the recovery catalog,

schema

Schema location of the table or view, required only when it is not in your login schema.

table

Name of a table or view.

dblink

Database link name for the database where the object exists, required only when it is not in the login database.

Examples

This example describes the V$CONTROLFILE table:

RMAN> desc v$controlfile
 Name                                      Null?    Type
 ----------------------------------------- -------- ----------------------------
 STATUS                                             VARCHAR2(7)
 NAME                                               VARCHAR2(513)
 IS_RECOVERY_DEST_FILE                              VARCHAR2(3)
 BLOCK_SIZE                                         NUMBER
 FILE_SIZE_BLKS                                     NUMBER
 CON_ID                                             NUMBER