What is an edition?

From: Mladen Gogala <mgogala_at_yahoo.com>
Date: Tue, 4 Nov 2008 21:11:51 +0000 (UTC)
Message-ID: <geqdqn$bu7$1@registered.motzarella.org>

Server is on Linux/x86. I noticed processes sometimes holding an "edition lock" on object ORA$BASE. The

V$LOCK_TYPE table says the following: "Prevent Dropping an edition in use ". To make things even more confusing,

there is a very well hidden view named '_CURRENT_EDITION_OBJECT'. Here is the text:

<code>select text
from dba_views where view_name = '_CURRENT_EDITION_OBJ';






case when (o.type# not in (4,5,7,8,9,10,11,12,13,14,22,87) or

bitand(u.spare1, 16) = 0) then


when (u.type# = 2) then

(select eo.name from obj$ eo where eo.obj# = u.spare2)



'ORA$BASE' end

from obj$ o, user$ u

where o.owner# = u.user#

and ( /* non-versionable object */

( o.type#
not in (4,5,7,8,9,10,11,12,13,14,22,87,88)

or bitand(u.spare1, 16) = 0)

/* versionable object visible in current edition */

or ( o.type# in (4,5,7,8,9,10,11,12,13,14,22,87)

and ( (u.type# <> 2 and

sys_context('userenv', 'current_edition_name') = 'ORA$BASE') TEXT

or (u.type#
= 2 and

u.spare2 = sys_context('userenv', 'current_edition_id'))

or exists (select 1 from obj$ o2, user$ u2

where o2.type#
= 88

and o2.dataobj# = o.obj#

and o2.owner# = u2.user#

and u2.type# = 2

and u2.spare2 =





) </code>

OK. Here are the questions:

What is the purpose of those "edition objects"? I figured out that it is about sys_context, but it's still unclear? The "CURRENT_EDITION_ID" option is not documented as a legal option for the SYS_CONTEXT function. What are the

users of type# 2? I don't have any in my databases. Users of type#=0 are roles, users of type#=1 are the normal lusers.

What in the world are the users of type#=2? Last but not least, what is protected by locks of the type AE? Did I mention

that there is no documentation about this on Metalink? Nada, nil, zilch. On version 10, "editions" are not recognized:

SQL> select sys_context('userenv','current_edition_id') from dual;

select sys_context('userenv','current_edition_id') from dual


ERROR at line 1:

ORA-02003: invalid USERENV parameter

Version 11 recognizes the arguments as correct:


SQL> select sys_context('userenv','current_edition_id') from dual;



I am an oracle beginner with only a few months of experience. Please, gurus, help me with my questions.

Received on Tue Nov 04 2008 - 15:11:51 CST

Original text of this message