update : 28-06-2017

DBA Script : example_drop_unused_column.sql

-- | FILE : example_drop_unused_column.sql |
-- +----------------------------------------------------------------------------+
-- | |
-- | |
-- | www.high-oracle.com |
-- |----------------------------------------------------------------------------|
-- | www.high-oracle.com |
-- |----------------------------------------------------------------------------|
-- | DATABASE : Oracle |
-- | FILE : example_drop_unused_column.sql |
-- | CLASS : Examples |
-- | PURPOSE : Example SQL syntax used to drop unused columns from a table. |
-- | NOTE : As with any code, ensure to test this script in a development |
-- | environment before attempting to run it in production. |
-- +----------------------------------------------------------------------------+
connect scott/tiger
set serveroutput on
Prompt ======================
Prompt DROP existing table...
Prompt ======================
Prompt
accept a1 Prompt "Hit to continue";
DROP TABLE d_table
/
Prompt =======================
Prompt CREATE TESTING TABLE...
Prompt =======================
Prompt
accept a1 Prompt "Hit to continue";
CREATE TABLE d_table (
id_no NUMBER
, name VARCHAR2(100)
, d_column VARCHAR2(100)
)
/
Prompt ========================
Prompt MARK COLUMN AS UNUSED...
Prompt ========================
Prompt
accept a1 Prompt "Hit to continue";
ALTER TABLE d_table SET UNUSED COLUMN d_column;
Prompt =======================================
Prompt QUERY ALL TABLES WITH UNUSED COLUMNS...
Prompt =======================================
Prompt
accept a1 Prompt "Hit to continue";
SELECT * FROM sys.dba_unused_col_tabs;
Prompt ======================================
Prompt PHYSICALLY REMOVE THE UNUSED COLUMN...
Prompt ======================================
Prompt
accept a1 Prompt "Hit to continue";
ALTER TABLE d_table DROP UNUSED COLUMNS;
Prompt ================================================
Prompt IF YOU WANTED TO PHYSICALLY REMOVE THE COLUMN...
Prompt ================================================
Prompt
accept a1 Prompt "Hit to continue";
-- ALTER TABLE d_table DROP COLUMN d_column;
Prompt =========================================
Prompt OPTIONALLY SYNTAX FOR REMOVING COLUMNS...
Prompt =========================================
Prompt
Prompt ALTER TABLE d_table DROP COLUMN d_column CASCADE CONSTRAINTS;
Prompt ALTER TABLE d_table DROP COLUMN d_column INVALIDATE;
Prompt ALTER TABLE d_table DROP COLUMN d_column CHECKPOINT 1000;
Prompt
accept a1 Prompt "Hit to EXIT";

End Script

Oracle Database Error Messages



Oracle Database High Availability Any organization evaluating a database solution for enterprise data must also evaluate the High Availability (HA) capabilities of the database. Data is one of the most critical business assets of an organization. If this data is not available and/or not protected, companies may stand to lose millions of dollars in business downtime as well as negative publicity. Building a highly available data infrastructure is critical to the success of all organizations in today's fast moving economy.

Well, the reason for above error is that i have taken the above script from a 11g database and running it on 10g database. 11g has bring some changes in password management. Below code is executed on 11g and user created successfully, which is expected result.