Comments on: Dropping and creating tables in read only tablespaces?!

By: Praveen N

Praveen N — Thu, 17 Nov 2011 20:59:48 +0000

Thanks for the post .
I have a question about sharing tablespaces using transportable TS :-
I share same read-only tablespace (same data files) between two different databases . When I drop a table from one database I can see the temporary segments like you said , but the same object in the other database has no impact even though it shares the same datafiles and tablespace . how?

By: John

John — Mon, 20 Sep 2010 06:49:13 +0000

Intersting behaviour.

Would make a good interview question: “When is read-only tablespace not read only?”

ans: When you use defered segment creation

By: basil

basil — Sat, 18 Sep 2010 14:58:36 +0000

Hi Tanel,

interesting as always. I wonder if is possible to recover a table partition dropped by accident which resides into a RO tablespace. The dba_segments still show it !

By: Noons

Noons — Thu, 09 Sep 2010 00:43:45 +0000

What happens if one drops the table, the temp segment is created, and then we drop the tablespace “including contents and datafiles”? Does it lose the temp segment?
I’m asking because I don’t have access to 11g to test.

By: Cloning RAC Database with RMAN fails with error | AskDba.org Weblog

Sun, 15 Aug 2010 17:54:27 +0000

[...] know that tables can be dropped from read-only tablespace. To know more about it, you can read this entry from Tanel describing this behavior Related Tags: 10g, rman Previous Topic: DBMS_SCHEDULER [...]

By: guojianjun

guojianjun — Wed, 21 Jul 2010 10:46:46 +0000

wonderful.

By: Blogroll Report 09/07/2010 – 16/07/2010 « Coskan’s Approach to Oracle

Blogroll Report 09/07/2010 – 16/07/2010 « Coskan’s Approach to Oracle — Fri, 16 Jul 2010 16:31:57 +0000

[...] 1-How does dropping and creating tables on read only tablespaces work? Tanel Poder-Dropping and creating tables in read only tablespaces?! [...]

By: Tanel Poder

Tanel Poder — Fri, 16 Jul 2010 04:16:06 +0000

@Uwe Hesse Good one!

By: Uwe Hesse

Uwe Hesse — Thu, 15 Jul 2010 15:33:31 +0000

Starting with 11gR2, there is also another behaviour if a user has CREATE TABLE privilege but no quota on the tablespace where the table is (intended to be) created: The CREATE TABLE succeeds! It is the same reason why you can create tables now in READ ONLY tablespaces – the DEFERRED SEGMENT CREATION. CREATE TABLE is then just modifiying the Data Dictionary, so no quota is needed as long as no insert tries to create the initial extend. Then an error is raised :-)

By: Tanel Poder

Tanel Poder — Mon, 12 Jul 2010 18:10:50 +0000

@Vishal Gupta Exactly, if Oracle documentation says one thing and expert X says another thing, but your testing shows a third thing, then you're right! Of course you need to validate whether your test has been correct and valid, that's where forums and peer review come into play :) Btw, you can also drop read only tables without a problem:


SQL> create table test as select * from all_users;

Table created.


SQL> alter table test read only;

Table altered.

SQL> delete test;
delete test
       *
ERROR at line 1:
ORA-12081: update operation not allowed on table "SCOTT"."TEST"


SQL> drop table test purge;

Table dropped.