Oracle Database Discussions

Server is 11.1.0.7 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<br />". 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';



TEXT

--------------------------------------------------------------------------------


select o."OBJ#",o."DATAOBJ#",o."OWNER#",o."NAME",o."NAMESPACE",o."SUBNAME",o."TY<br /><br /><br />PE#",o."CTIME",o."MTIME",o."STIME",o."STATUS",o."REMOTEOWNER",o."LINKNAME",o."FL<br /><br /><br />AGS",o."OID$",o."SPARE1",o."SPARE2",o."SPARE3",o."SPARE4",o."SPARE5",o."SPARE6",




o.spare3,

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

null


when (u.type# = 2) then

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

else



TEXT

--------------------------------------------------------------------------------


'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# &lt;&gt; 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 =

sys_context('userenv',
'current_edition_id'))

)



TEXT

--------------------------------------------------------------------------------

)

) </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&gt; 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:

Connected.

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



SYS_CONTEXT('USERENV','CURRENT_EDITION_ID')

--------------------------------------------------------------------------------

99









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