Alter table tablename drop column col

I tried to drop a column from a table created by sys user. Being a sys user I am unable to drop the column. Please explain.
SQL> alter table test move tablespace users;
Table altered.
SQL> alter table test drop column two;
alter table test drop column two
ERROR at line 1:
ORA-12988: cannot drop column from table owned by SYS
Here two is the column name.
Regards
Vijay Kumar

Hello Gasparotto
It is amazing to me. Being a sys user I created a table and then I tried to alter the table by dropping a column but it is giving me error as I have already stated. Please explain over this issue.
Regards
Vijay Kumar

Similar Messages

ALTER TABLE vs DROP/CREATE statements

Hello Everyone,
I have created a script in order to update our database which includes adding new columns to a table. However, database changes and script generation must now be done using the Erwin data modeler and script generated using a compare option (within Erwin) which compares the model with the actual database.
I had a script of a few lines with a few ALTER TABLE ...ADD COLUMN statements to add the new columns.
Now, in Erwin, instead of generating 'ALTER TABLE...ADD COLUMN statements, Erwin has generated an ALTER TABLE...RENAME and CREATE TABLE statements which as a side effect will drop/re-create the table, all of it's indexes, constraints, foreign keys, etc.
Instead of a few simple "hand written" lines to run a fast script, the script is a few pages long with all of those DROP/CREATE statements, which makes the script way too much complicated and takes much longer to run.
And this, even though the Erwin option "USE ALTER TABLE ADD COLUMN" statement to create columns.
I was told that the DROP/CREATE is normal and that this is the way it should be done.
Am I out of it by thinking that it should use ALTER TABLE ADD COLUMN statements to add new columns to a table and not the DROP/CREATE methodology ? Am I missing something ? Do these new "data thinkers" know something that I am missing ?
Makes me think of the 80s when people were generating dBase application with the included application generator and were ending up with all kinds of useless and non efficient code.
Any though on this ? Am I out in the field ?
Thank you.

Thank you both for your replies.
Neil,
I didn't think that adding new blank columns using the ALTER TABLE ADD COLUMN statement would make the table more fragmented than it already was to begin with.
I would have think that this kind of maintenance would take place on it's own, outside of a new deployment release.
I have always used the ALTER TABLE ADD COLUMN instead of the DROP/CREATE TABLE statements to add new columns to a table because of the simplicity, speed and lower risk involved compare to dropping a table and all of it's objects then re-create all of them and doing an import.
What do any of you do when you need to add new columns to a table ? Use the drop table and re-create or the ALTER TABLE ADD COLUMN ?
Any comments welcome.
Thanks again.

Alter table add new column

I have table structure like this
select
PROJECT_NAME, OBJECT_NAME, INCOMMING_DOC, DESIGN, DESIGN_REVIEW, DESIGN_REWORK, BUILD, BUILD_REVIEW, BUILD_REWORK, TEST_CASE_PREP, TEST_CASE_REVIEW, TEST_CASE_REWORK, INSTALLATION_SCRIPT, UNIT_TESTING, WAIT_TIME, COMMENTS, INITIAL_DATE
from initial_effort
i want to add a column after unit_testing
How to include
Thanks
Sudhir

Directly you can add the column in existing table, No matter which position column find in the table, Its depend on your SELECT Statement. You add column in the table like this..
ALTER TABLE TEST
ADD COL_NAME DATATYPE CONSTRAINTS
OR
Rename your table table , Take the same table creation script add your column whereever you want.
Run the script and drop the old table.

Alter table type from COLUMN to ROW

TABLE type can be changed from ROW to COLUMN (and vice versa) using the ALTER TABLE command .
Lars Breddemann wrote
when considering which data store to choose (which, by the way, can be changed later on as well), you have to take into account:
* will you usually need the complete row (all columns)? If so, row store may be more efficient, as reconstructing the complete row is one of the most expensive column store operations.
* will you need to join the row-store table to a column store table? If so, you should avoid using a different storage type, since using both storage engines in a statement leads to intermediate result set materialization which is another name for bad performance.
* do you want to fill the table with huge amounts of data, that should be aggregated and analysed? If this is the case, the column store is the better option.
As a rule of thumb you may just start with column-store tables and change them to row-store tables when you encounter performance issues.
In general most developers cannot anticipate all important use cases for the tables they design.
This is especially true for living and growing systems.
So, more important than choosing the 'right' storage in the beginning is to monitor the performance and to benchmark the differences when changing the storage engine.
So suppose we have a COLUMN table , but would be requiring to get data from many columns (so would be a very expensive column operation) , would it be advisable to change the table type FROM COLUMN to ROW on the fly . would this be a resource intensive operation if the table has a lot of data ?
Lets suppose , if the above can be done , but there exists a interdependency for the column table (say from another simultaneous operation) , and thus should remain as COLUMN table as such . so what would be the better option in this case .
Creating views is not an option as it seems from the SQL guide , that there was not an option to create a ROW view from a COLUMN table. ?
Edited by: Rajarshi Muhuri on Nov 27, 2011 3:25 AM

Dear Rajashri,
1. you cann't alter table from column to row using alter command.
but you can achieve this through Stored procedure, just Little bit HSQL coding.
I hope upcoming versions SAP Gives like following SQL statements ( following statemnt not works in HANA works in oralce )
   create row table "EFASHION_TUTORIAL"."AAA" as
select
"ARTICLE_COLOR_LOOKUP_ID",
"ARTICLE_ID",
"COLOR_CODE",
"ARTICLE_LABEL",
"COLOR_LABEL",
"CATEGORY",
"SALE_PRICE",
"FAMILY_NAME",
"FAMILY_CODE"
from "EFASHION_TUTORIAL"."ARTICLE_COLOR_LOOKUP";
2. Row & column table two different purpose like OLTP & OLAP.
     when you think about OLAP means modeling use Column.
      when you think about OLTP means real time operations then use Row
Column table is high compress ( 5 - 20X), i don't think you want get any performance issue when read information from column table. that is actual Core engine reading parller process. ( that is Heart of HANA).
Column table purpose quite different like calculations, grouping.. most of DW environment Queires.
Row table is currently system tables in feature row tables as OLTP, it's less compress mode compress to column store.
so finally you write small program convert column to row and row to column
thanks
Rao

What view will show me where tables are 'alter table tablename parallell;'

10g R2 Windows 64
Hi,
I'm in a bind and am currently searching the manuals for this. I expected to see a column for this in all_tables but don't see anything related to parallelism. Is there a view I can use to see if a table has been altered to use parallelism?
Thanks.
Brian

Degree column in the view USER_TABLE will show the current parallel degree of the table, but there is no way to tell whether the table was created with the same degree or was altered after creation.

Drop column from compressed table

NLSRTL
11.2.0.3.0
Production
Oracle Database 11g Enterprise Edition
11.2.0.3.0
64bit Production
PL/SQL
11.2.0.3.0
Production
TNS for Linux:
11.2.0.3.0
Production
Hello,
I read about how to drop column from a compressed table - first set it unused and then drop the unused columns. However, in the example below on the database I ran it, it does not work. Please, can you tell me WHEN this approach does not work. What it is dependent on - parameters or something else. Why I cannot drop the unused columns?
And the example along with the errors:
create table tcompressed compress as select * from all_users;
> table TCOMPRESSED created.
alter table tcompressed add x number;
> table TCOMPRESSED altered.
alter table tcompressed drop column x;
>
Error report:
SQL Error: ORA-39726: unsupported add/drop column operation on compressed tables
39726. 00000 - "unsupported add/drop column operation on compressed tables"
*Cause:    An unsupported add/drop column operation for compressed table
           was attemped.
*Action:   When adding a column, do not specify a default value.
           DROP column is only supported in the form of SET UNUSED column
           (meta-data drop column).
alter table tcompressed set unused column x;
> table TCOMPRESSED altered.
alter table tcompressed drop unused columns;
>
Error report:
SQL Error: ORA-39726: unsupported add/drop column operation on compressed tables
39726. 00000 - "unsupported add/drop column operation on compressed tables"
*Cause:    An unsupported add/drop column operation for compressed table
           was attemped.
*Action:   When adding a column, do not specify a default value.
           DROP column is only supported in the form of SET UNUSED column
           (meta-data drop column).
As you can see even after altering the table by setting the column X as unused I still cannot drop it by using DROP UNUSED COLUMNS.
Thank you.

check this link it might help. At the end it has also mentioned of a bug check the same.
http://sharpcomments.com/2008/10/ora-39726-unsupported-adddrop-column-operation-on-compressed-tables.html

Cannot drop column from table owned by SYS

Hello everybody,
How can I drop a column of table which is owned by sys? thanks!
Result as follows:
SQL> ALTER TABLE HELLO_TB DROP COLUMN NUM;
ALTER TABLE HELLO_TB DROP COLUMN NUM
ERROR at line 1:
ORA-12988: cannot drop column from table owned by SYS
newbie v

You can not 'change' the ownership.
You can, however, 'move' or 'clone' most objects by exporting and importing. As follows:
I create a table under SYS (shudder).
I then export it
- using userid SYS in this case,
- under normal circumstances I'd either use a DBA account or the owner's userid
- since I want a table, I use the TABLES option - a list is comma separated and in quotes
I then import it using a 'userid' switch - fromuser & touser options
- in this case from SYS to HR
Finally, I verify it was transported.
Actual console session in Linux follows:
pop2@fuzzy:~> sqlplus / as sysdba
SQL*Plus: Release 10.2.0.1.0 - Production on Fri Mar 10 19:58:01 2006
Copyright (c) 1982, 2005, Oracle. All rights reserved.
Connected to:
Oracle Database 10g Express Edition Release 10.2.0.1.0 - Production
SQL> create table test1 ( x1 number );
Table created.
SQL> insert into test1 values (2);
1 row created.
SQL> select * from test1;
        X1
         2
SQL> Disconnected from Oracle Database 10g Express Edition Release 10.2.0.1.0 - Production
pop2@fuzzy:~> exp file=exp.dmp tables='TEST1'
Export: Release 10.2.0.1.0 - Production on Fri Mar 10 20:00:07 2006
Copyright (c) 1982, 2005, Oracle. All rights reserved.
Username: sys/????? as sysdba
Connected to: Oracle Database 10g Express Edition Release 10.2.0.1.0 - Production
Export done in AL32UTF8 character set and AL16UTF16 NCHAR character set
About to export specified tables via Conventional Path ...
. . exporting table                          TEST1          1 rows exported
Export terminated successfully without warnings.
pop2@fuzzy:~> imp file=exp.dmp fromuser=sys touser=hr
Import: Release 10.2.0.1.0 - Production on Fri Mar 10 20:00:44 2006
Copyright (c) 1982, 2005, Oracle. All rights reserved.
Username: sys/????? as sysdba
Connected to: Oracle Database 10g Express Edition Release 10.2.0.1.0 - Production
Export file created by EXPORT:V10.02.01 via conventional path
import done in AL32UTF8 character set and AL16UTF16 NCHAR character set
. importing SYS's objects into HR
. . importing table                        "TEST1"          1 rows imported
Import terminated successfully without warnings.
pop2@fuzzy:~> sqlplus hr/hr
SQL*Plus: Release 10.2.0.1.0 - Production on Fri Mar 10 20:00:57 2006
Copyright (c) 1982, 2005, Oracle. All rights reserved.
Connected to:
Oracle Database 10g Express Edition Release 10.2.0.1.0 - Production
SQL> select * from test1;
        X1
         2
SQL>The export/import pair are incredibly powerful - and few people understand them well. If you are interested in digging into their capability, check out their chapters in the Utilities manual (under the Books tab) at http://www.oracle.com/pls/db102/portal.portal_db?selected=1

Dropping a column in composite xmltype table with virtual column

Hello,
i found some interesting behavior. I have a table with xmltype column and a virtual column. If i drop a column, which has an index smaller than the index for the xmltype column, than the virtual column reference for xmltype column is not changed.
select * from v$version;
drop table t_xml purge;
create table t_xml( c1 number,
                    c2 number,
                    cxml xmltype,
                    c3 number,
                    xmlflag number as (nvl2(cxml,1,0)));
select * from t_xml;
alter table t_xml drop column c2;
select * from t_xml; The 2nd select will result in error:
SQL> select * from v$version;
BANNER
Oracle Database 11g Enterprise Edition Release 11.2.0.1.0 - 64bit Production
PL/SQL Release 11.2.0.1.0 - Production
CORE    11.2.0.1.0      Production
TNS for IBM/AIX RISC System/6000: Version 11.2.0.1.0 - Production
NLSRTL Version 11.2.0.1.0 - Production
SQL> alter table t_xml drop column c2;
Tabelle wurde geändert.
SQL>
SQL> select * from t_xml;
select * from t_xml
FEHLER in Zeile 1:
ORA-00904: "SYS_NC00004$": ungültiger BezeichnerNow the virtual column xmlflag references still the old hidden column for cxml (SYS_NC00004$). It not references the new hidden column, which is now SYS_NC00003$.
I think, it is a bug! Can someone inform oracle? I have no access to metalink.

Hi,
Please try this code:
loop at int_inv into wa_inv.
    lv_count = lv_count + 1.
    AT END OF posnr.   <------- The field you want to sum..
      gs_total-posnr      = wa_inv-posnr.
      gs_total-cov_total = lv_count.
      APPEND gs_total TO gt_total.
      CLEAR : gs_total,
              lv_count,
              wa_inv.
    ENDAT.
ENDLOOP.

How to alter table in sql server2008

Hi Friends, I have import one table and want to alter table. How do i do this

Hi ,
YOu need Alter Command for the same. but you have to specify what you want to Alter.
For Reference
To add a column in a table, use the following syntax:
ALTER TABLE table_name
ADD column_name datatype
To delete a column in a table, use the following syntax (notice that some database systems don't allow deleting a column):
ALTER TABLE table_name
DROP COLUMN column_name
To change the data type of a column in a table, use the following syntax:
ALTER TABLE table_name
ALTER COLUMN column_name datatype
http://www.techonthenet.com/sql/tables/alter_table.php
http://www.tutorialspoint.com/sql/sql-alter-command.htm
Thanks
Please Mark This As Answer or vote for Helpful Post if this helps you to solve your question/problem.

Dealing with errors due to newly added/dropped columns

DB version:11g
I am not sure if i have created an unnecessarily large post to explain a simple issue. Anway, here it is.
I have been asked to code a package for Archiving .
We'll have two schemas;The original schema and an Archive schema (connected via a DB Link)
ORIGINAL Schema -------------------------> ARCHIVE Schema
               via DB Link          When records of certain tables in the ORIGINAL schema meet the archiving criteria (based on Number of Days Old, Status Code etc), it will be moved ('archived') to the ARCHIVE schema using the INSERT syntax
insert into arch_original@dblink
col1,
col2,
col3,
select col1,
col2,
col3,
from original_tableThe original table and its archive table has the same structure, except that the Archive table has an additional column called archived_date which just records when a record got archived.
create table original
col1 varchar2(33),
col2 varchar2(35),
empid number
create table arch_original
col1 varchar2(33),
col2 varchar2(35),
empid number,
archived_date date default sysdate not null
);We have tables with lots of columns(there are lots of tables with more than 100 columns) and when all column names are explicitly listed like the above syntax, the code becomes huge.
Alternative Syntax:
So i thougt of using the syntax
insert into arch_original select original.*,sysdate from original; -- sysdate will populate archived_date columnEventhough the code looks simple and short, i've noticed a drawback to this approach.
Drawback:
For the next release, if developers decide to add/drop a column in the ORIGINAL table in the Original Schema, that change should be reflected in the archive_table's (ARCHIVE schema) DDL script as well. It is practically impossible to keep track of all these changes during the development phase.
If i use
insert into arch_original select original.*,sysdate from original; syntax, you will realise that there is change in the table structure only when you encounter an error(due to missing/new column) in the Runtime. But, if you have all the column names listed explicitly like
insert into arch_original@dblink
(col1,
col2,
col3,
select col1,
col2,
col3,
from original_tablethen you'll encounter this error during the Compilation itself. I prefer the error due to a missing/new column during the Compilation itself rather than in Runtime.
So what do you guys think? I shouldn't go for
insert into arch_original select original.*,sysdate from original; syntax because of the above Drawback. Right?

What advantage would it bring if i make ARCHIVED_DATE as the first column in the ARCHIVE tables?The advantage is that if you'll add a column in the future on both original and archived tables the insert statement will work anyway...
SQL> create table x (a number, b number);
Table created.
SQL> create table y (arc_date date, a number, b number);
Table created.
SQL> insert into x values (1,1);
1 row created.
SQL> insert into x values (2,2);
1 row created.
SQL> select * from x;
         A          B
         1          1
         2          2
SQL> insert into y select sysdate, x.* from x;
2 rows created.
SQL> alter table x add (c number);
Table altered.
SQL> alter table y add (c number);
Table altered.
SQL> alter table x drop column b;
Table altered.
SQL> alter table y drop column b;
Table altered.
SQL> insert into x values (3,3);
1 row created.
SQL> insert into y select sysdate, x.* from x
2 where a=3;
1 row created.
SQL> select * from x;
         A          C
         1
         2
         3          3
SQL> select * from y;
ARC_DATE           A          C
25-JAN-10          1
25-JAN-10          2
25-JAN-10          3          3Max
[My Italian Oracle blog|http://oracleitalia.wordpress.com/2010/01/23/la-forza-del-foglio-di-calcolo-in-una-query-la-clausola-model/]
Edited by: Massimo Ruocchio on Jan 25, 2010 12:44 PM
Added more explicative example

Commit after alter table statement or not?

Hi,
Is it necessary to put the a commit after the following statement or is it automatically committed:
Alter table tab_name drop column col_name;
Thanks

Khurram,
Isnt Eric you are , i mean isnt yours synonym :)Erm...simple answer. No. We are not the same person. I just know that Eric, like yourself, makes good contributions to these threads and then someone like that is coming on the forums and trying to make himself look better and put down the regular contributors which isn't really on is it, I think you'll agree.
CREATE PUBLIC SYNONYM Eric FOR Blushadow;
hehe.

Alter table reaching the max number of char 4000, CLOB? NCLOB?

I have a column is a table defined as a VARCHAR2(4000)
I try to alter the table
alter table sybaapc
MODIFY SYBAAPC_EXTRACURRICULAR VARCHAR2(5000)but it give me this error
ORA-00910: specified length too long for its datatype
I want the users to be able to enter more information on that column.
It seems that 4000 is the max we are in Oracle 10g
can I changed to CLOB or nclob, we already have data in that table?
What are the implications of changing it to clob or nclob,

Thats becuase the maximum character length for a table column is 4000.
Alternatively you can:
SQL> create table test_1 (col1 VARCHAR2(4000))
2 /
Table created.
SQL> insert into test_1 values(RPAD('*',4000,'*'));
1 row created.
SQL> commit;
Commit complete.
SQL> alter table test_1 modify (col1 clob);
alter table test_1 modify (col1 clob)
ERROR at line 1:
ORA-22858: invalid alteration of datatype
SQL> alter table test_1 add(col2 clob);
Table altered.
SQL> update test_1 set col2 = col1;
1 row updated.
SQL> commit;
Commit complete.
SQL> alter table test_1 drop column col1;
Table altered.
SQL> alter table test_1 rename column col2 to col1;
Table altered.
SQL> desc test_1
Name Null? Type
COL1 CLOB
SQL>
SQL> select * from test_1;
COL1
SQL> Edited by: AP on Aug 24, 2010 7:41 AM

Problem dropping column in sqlplus.

I write
alter table u_gotobank drop column u_bacdamnt;
and it says i'm missing a key word at column.
what could be the problem?

Jens, I don't think that's the problem :
SQL> desc test10
Name                                      Null?    Type
X                                                  NUMBER
Y                                                  CHAR(1)
Z                                                  CHAR(1)
W                                                  CHAR(1)
SQL> alter table test10 drop column w;
Table altered.
SQL>

To drop column of view

hello all
i would like to drop one of column of view.
but i unable to drop.
ashish>alter view magazine drop column author;
alter view magazine drop column author
ERROR at line 1:
ORA-00905: missing keyword
but same process i had done on table which work.
ashish>ed
Wrote file afiedt.buf
1* alter table magazines drop column author
ashish>/
Table altered.
can u please tell me why i m fail to do so??
with regards
ashish

A view is nothing more than a stored query, change the query and you change the view.
SQL> create view vw
2 as
3 select object_name
4       , object_type
5    from all_objects
6   where rownum < 10
7 /
View created.
SQL> select *
2    from vw
3 /
OBJECT_NAME                    OBJECT_TYPE
/1005bd30_LnkdConstant         JAVA CLASS
/10076b23_OraCustomDatumClosur JAVA CLASS
/10297c91_SAXAttrList          JAVA CLASS
/103a2e73_DefaultEditorKitEndP JAVA CLASS
/1048734f_DefaultFolder        JAVA CLASS
/10501902_BasicFileChooserUINe JAVA CLASS
/105072e7_HttpSessionBindingEv JAVA CLASS
/106ba0a5_ArrayEnumeration     JAVA CLASS
/106faabc_BasicTreeUIKeyHandle JAVA CLASS
9 rows selected.
SQL> create or replace view vw
2 as
3 select object_name
4    from all_objects
5   where rownum < 10
6 /
View created.
SQL> select *
2    from vw
3 /
OBJECT_NAME
/1005bd30_LnkdConstant
/10076b23_OraCustomDatumClosur
/10297c91_SAXAttrList
/103a2e73_DefaultEditorKitEndP
/1048734f_DefaultFolder
/10501902_BasicFileChooserUINe
/105072e7_HttpSessionBindingEv
/106ba0a5_ArrayEnumeration
/106faabc_BasicTreeUIKeyHandle
9 rows selected.
SQL>You beat me to it, Rob. And you're absolutely right about the triggers!
Message was edited by:
Alex Nuijten

Drop column impact on dependencies

Hello,
i dropped a column on a table,, which was fine, but i have a view and package. when a drop a column from a table will not automatically drop from the view? do i have to alter view test drop column exra_col;
could someone let me know how to handle this...
Thank you..

Have you tried putting a test case together?
SQL > SELECT * FROM V$VERSION;
BANNER
Oracle Database 11g Enterprise Edition Release 11.2.0.2.0 - Production
PL/SQL Release 11.2.0.2.0 - Production
CORE    11.2.0.2.0      Production
TNS for 32-bit Windows: Version 11.2.0.2.0 - Production
NLSRTL Version 11.2.0.2.0 - Production
SQL > CREATE TABLE TEST
2 ( col_a NUMBER
3 , col_b NUMBER
4 , col_c NUMBER
5 );
Table created.
SQL > CREATE VIEW TEST_VIEW
2 AS
3 SELECT col_a
4       , col_b
5       , col_c
6 FROM   test
7 ;
View created.
SQL > SELECT * FROM test_view;
no rows selected
SQL > ALTER TABLE TEST DROP COLUMN col_c;
Table altered.
SQL > SELECT * FROM test_view;
SELECT * FROM test_view
ERROR at line 1:
ORA-04063: view "TEST.TEST_VIEW" has errors
SQL > CREATE OR REPLACE VIEW TEST_VIEW
2 AS
3 SELECT col_a
4       , col_b
5 FROM   test
6 ;
View created.
SQL > SELECT * FROM test_view;
no rows selected
SQL >

Alter table tablename drop column col

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