Wednesday, December 07, 2011

Two faced dual?

Anyone witnessed this before?

SQL> select * from dual;

-------- ---------- ---------- -
03A00074 0 1 X

SQL> desc dual
Name Null? Type
----------------------------------------- -------- -----------

SQL> select * from dual;



Happened during startup of the instance. 10GR2 EE on MS Win XP.

Friday, December 02, 2011 - oh yeah!

Ended up restoring databases, the other day, due to:
If the tool runs successfully, the two tables
orasso.wwsso_papp_configuration_info$ and orasso.wwsec_enabler_config_info$
will not be empty.
However, there are cases when does not complete successfully and
hence leaving these two tables not populated.
In these case, restore the two tables from a orasso schema DB backup.

Well, I ended "in these case". And those two tables empty means no OC4J_SECURITY starting, no SSO.
OID works, though...

By the way - if you think restoring the ORASSO schema undoes all changes made by, think again. See metalink Your Oracle Support Doc ID 435483.1

Monday, November 07, 2011

APEX PDF Printing II and ORA-20001 "Printing Engine"

If you use APEX PDF printing with an 11G database, make sure you configure the acl. 11G does NOT allow alless to the www by default!
When you run into this error:

ORA-20001: The printing engine could not be reached because either the URL specified is incorrect or a proxy URL needs to be specified

Then, try this:
description => 'ACL for ApEx Printing',
principal => 'APEX_040100'
is_grant => true,
privilege => 'connect');

principal => 'APEX_040100',
is_grant => true,
privilege => 'resolve');

host => '');

Wednesday, October 12, 2011

Oracle DIP filtering

In the course of a major redesign of AD Domains at the site I work for, the question arose how to select only those users, which completely migrated to the consolidated domain.
It was impossible to just wait with moving these accounts into the groups, defined as source for synchronization, as it was equally impossible to delete these accounts from the "old" domains.
All in all, there was to be a fortnight overlap, during which accounts would be 'active' in both domains.

Now, it just proves there's yet another meaning to the word "Single" in Single Sign On server: the scenario described above will cause SSO/WNA to fail.
Which is understandable: upon inspection of the user credentials, two entries are found, and there's no way of telling which should be used (well, actually there is by inspecting the Kerberos ticket, but it is not implemented for good reason).

The Problem

After identifying the SSO/WNA problem, synchronization from the new domain was halted, and users removed from OID. However, there were several parties involved, that could simply not wait for the complete consolidation to be completed. Those parties had consolidated into the new environment, and needed back SSO/WNA. Other parties, yet to be migrated, were not eager to loose their SSO/WNA for at least two weeks.

So: catch-22, rock-and-hard-place, etc...

Working towards the solution

First of all, I implemented separate synchronization profiles for users and groups. There are two blog entries: one on user synchronization, and another one on group synchronization.

Then, the filtering needed to be adapted in order to allow for a simple alteration of the contents of a field to signal completion. Now, I know filtering on basis of exsistance of objectclasses, but not really on the contents. Given some examples in the documentation, it sould be possible.
After some testing, I came up with:


This allows for Descriptions in Active Directory like "User has been granted access to Oracle", or just simply "oracle" - as long as there's the word "oracle" somewhere in the description.

Of course, you may want to use another attribute.

Monday, October 10, 2011

Edit your export dmp-file: never?


Every expert in the field will tell you to never, ever edit your dump file.
And rightfully so. Unless you really are caught between a rock and a hard place, and think you know what you are doing. I think I know.

Fair warning: you are about to see stunts that should not be attempted at home. Do not perform these actions without supervision of experienced personnel.
And never use a text editor.


The scenario is this: you are under a time constraint (deadlines!). You have a dump file, exported from a WE8ISO8859P1 database, using .WE8ISO8859P1 as character set part of the NLS_LANG setting.
You are about to import this into a WE8MSWIN1252 database.
Now, with the latest "smart" additions to exp and imp, you are bound to get "Warning: possible character set conversion" in you log file.
Either because you use WE8ISO8859P1, and imp recognizes the dump file uses that, too, but the database isn't, or because you use WE8MSWIN1252 for NLS_LANG, and imp recognizes your dump file uses WE8ISO8859P1.
Both ways, your Euro ('€') character will become "unmapped" or "unknown": 0xBF (191 decimal): '¿'


There's one Quick and Dirty way to get rid of this: edit your dump file, and change the header record, that defines the character set used.
Bytes 2 and three define the character set used. Use this to find the values:
select nls_charset_id(value) id,
value Charset_name
from v$nls_valid_values
where parameter = 'CHARACTERSET'
and nls_charset_id(value) is not null
and value like 'WE8%';
That will give you a list, amongst which these entries:
---------- ----------------------------------------------------------------
10 WE8PC850
27 WE8EBCDIC1148
28 WE8PC858
31 WE8ISO8859P1
39 WE8ISO8859P9
46 WE8ISO8859P15
178 WE8MSWIN1252
210 WE8GCOS7

Now, let's see how this could work under MS Windows. The premium hex tool under MS Windows is debug! And as long as your dump file fits, this is feasable:

H:\werk\coters<debug pasfotos.dmp
136F:0100 03 00 1F 45 58 50 4F 52-54 3A 56 30 37 2E 30 33 ...EXPORT:V07.03
136F:0110 2E 30 34 0A 44 43 4F 54-0A 52 54 41 42 4C 45 53 .04.DCOT.RTABLES
136F:0120 0A 32 30 34 38 0A 30 0A-00 20 20 20 20 20 20 20 .2048.0..
136F:0130 20 20 20 20 20 20 20 20-20 20 20 20 20 20 20 20
136F:0140 20 20 20 20 20 20 20 20-20 20 20 20 20 20 20 20
136F:0150 20 20 20 20 20 20 20 20-20 20 20 20 20 20 20 20
136F:0160 20 20 20 20 20 20 20 20-57 65 64 20 44 65 63 20 Wed Dec
136F:0170 31 33 20 31 32 3A 32 38-3A 35 35 20 32 30 30 30 13 12:28:55 2000
136F:0102 1F.B2
Writing 0E800 bytes

What you can see here, is opening a (yes, small) export file, called pasfotos.dmp, in debug. I then dump (command: d) 8 lines. Line 1 contains 0x03, 0x00, 0x1f.
Bytes 2 and 3 are the character set identifiers: 0x001f translates into 31 decimal, or: WE8ISO8859P1.
That is correct, this over 10 years old file was dumped from a WE8ISO8859P1 database.
I can also edit this file: e0102 (edit position 0102). debug prompts the old value (1F), and allows me to enter a new (B2) value.
I then write back the file (command w), and quit debug (q). I can open the same file again, to show you the change:

H:\werk\coters>debug pasfotos.dmp
136F:0100 03 00 B2 45 58 50 4F 52-54 3A 56 30 37 2E 30 33 ...EXPORT:V07.03
136F:0110 2E 30 34 0A 44 43 4F 54-0A 52 54 41 42 4C 45 53 .04.DCOT.RTABLES
136F:0120 0A 32 30 34 38 0A 30 0A-00 20 20 20 20 20 20 20 .2048.0..
136F:0130 20 20 20 20 20 20 20 20-20 20 20 20 20 20 20 20
136F:0140 20 20 20 20 20 20 20 20-20 20 20 20 20 20 20 20
136F:0150 20 20 20 20 20 20 20 20-20 20 20 20 20 20 20 20
136F:0160 20 20 20 20 20 20 20 20-57 65 64 20 44 65 63 20 Wed Dec
136F:0170 31 33 20 31 32 3A 32 38-3A 35 35 20 32 30 30 30 13 12:28:55 2000

Obviously, 0xB2 is 178 decimal, and that is the characterset id for MSWIN1252.

My file is much larger, I don't like debug

or whatever. Luckily, there is this nifty app, that allows for larger files to be hacked. Usage is simple:

dmp2utf8 <filename> [charset id]
Default is UTF8, or charset id 871 (0x0367). There are some othe nice gems on this site,

On Unix, or Linux, you would use hexedit, or even sed.

Wednesday, June 29, 2011

Upgrading VirtualBox

It wasn't as easy as though, so here's the drill:

sudo apt-get install virtualbox-4.0
If you get errors about trust/keys/whatever, do:
wget -q -O- | sudo apt-key add -
then, retry the above.

wget -q
chmod 744 Oracle_VM_VirtualBox_Extension_Pack-4.0.10-72436.vbox-extpac
VBoxManage extpack install Oracle_VM_VirtualBox_Extension_Pack-4.0.0-69151.vbox-extpac

add yourself to the vboxusers group:
usermod -G vboxusers frank

Thursday, May 26, 2011

SSO Fails randomly; clock skew too great

Ran against some weird issues today. At random people failed to pass Single Sign On. Not until I started to monitor the OC4J Security logging (in $ORACLE_HOME/opmn/logs) that I saw a failure

GSSException raised: Failure unspecified at GSS-API level (Mechanism level: Clock skew too great (37))

The Kerberos configuration file allows for a defined clock skew, and has a default of 300 (units: seconds).
There was no such entry in /etc/krb5, so the default was used.


Comparing system date&time against the timestamps written in the logs, I noticed indeed a difference of a little over 5 minutes. That explained the error, which was correct (too much time difference indicates a security breach, according to Kerberos)
Restarting the services resolved that, but this is not what you want in a 24x7 operation.


Then, I recalled an issue with Java internal clocks slowly running out of sync with the operating system clock - seems specific for HP-UX, and can be resolved by specifying
in the options section of the process at hand.

More specifics: the error code in full:

11/05/24 08:13:28 GSSException raised: Failure unspecified at GSS-API level (Mechanism level: Clock skew too great (37))
11/05/24 08:13:28 GSSException: Failure unspecified at GSS-API level (Mechanism level: Clock skew too great (37))
11/05/24 08:13:28 at
11/05/24 08:13:28 at
11/05/24 08:13:28 at
11/05/24 08:13:28 at Source)
11/05/24 08:13:28 at Source)
11/05/24 08:13:28 at com.evermind.server.http.EvermindHttpServletRequest.getUserPrincipalInternal(EvermindHttpServletRequest.j
11/05/24 08:13:28 at com.evermind.server.http.HttpApplication.authenticate(
11/05/24 08:13:28 at com.evermind.server.http.HttpApplication.getRequestDispatcher(
11/05/24 08:13:28 at com.evermind.server.http.HttpRequestHandler.processRequest(
11/05/24 08:13:28 at
11/05/24 08:13:28 at
11/05/24 08:13:28 at com.evermind.util.ReleasableResourcePooledExecutor$
11/05/24 08:13:28 at

A snippet from the opmn.xml file, after the change:

<category id="start-parameters">
<data id="java-options" value="-server -XX:+UseGetTimeOfDay -Djava.awt.headless=true -Xmx512m

Remember to update all Oracle internals:

$ORACLE_HOME/dcm/bin/dcmctl updateconfig -ct opmn
$ORACLE_HOME/opmn/bin/opmnctl reload

Derived from Oracle note 352466.1 (which states the clock runs too fast...)

Monday, May 23, 2011

FireFox 4 breaks Oracle SSO

I can no longer do SSO on Oracle application servers, using mod_osso with Firefox 4. Some problems with SPNEGO have been "solved", breaking SSO.

Will be investigated, and continued. For now - do NOT move to FF4!

Friday, April 15, 2011

Qubes: A Secure Operating System

This might be interesting for all you system operators out there: a secure OS!
I see potential for Oracle as well.

You may download from here which is a basic installation guide as well.

Hats off for Joanna - she may have something here. Now we wait for buyers to emerge, and incorporate it in something we'll all have to pay for big time.

[update 4-sep-2012]
Version 1.0 has been released!

Thursday, April 07, 2011

I'd like that: FTTH

Deutschen Telekom offers Fiber To The home, with internet (100Mbps download, 50 Mbps upload) and telephone for less than 50 Euro monthly.
That's about what I pay for 5Mbps down/1Mbps up.

An extra 10 bucks will get you Digital Television as well. Unfortunately, delivery ends just at the other side of the border, in spite of this:

Tuesday, March 29, 2011

Long time no see

You did not see updates for some time. One of the reasons is the NZ earth quake. My son lives in Christchurch.
Another reason is work, which is very hectic, to say the least.


Wednesday, January 05, 2011