Software Engineer Thoughts

Written by Paweł Barut
As you know in Oracle 11g passwords are case sensitive by default. This applies to connecting via SQL*Plus or other client tools. And it also applies to database links between databases. So when you link from Oracle 10g to Oracle 11g create database link like this:

CREATE DATABASE LINK my_link
CONNECT TO remote_user IDENTIFIED BY "CaSe_SeNsItIvE_PaSsWoRd"
USING 'TNS_ID_11G';

Do not forget to enclose password by double-quote marks!
When you do not set password this way, you will be getting:

ORA-01017: invalid username/password; logon denied.

Hope this small tip will be useful for someone.

Paweł

More on Creating Database Links.

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Written by Paweł Barut
Some time ago I've had noticed strange problem with XMLRoot function. I was installing application on production server and I've noticed that code:

SQL> select XMLRoot(xmltype('<a>a</a>'))
2 from dual;

gives error:

select XMLRoot(xmltype('<a>a</a>'))
*
Error in line 1:
ORA-00904: "XMLROOT": invalid identifier

WTF, it was running perfectly on development and test environment!
Quick search revealed that XMLROOT is function in XDB schema, which was missing in production environment. I've just copies source code for function from test environment and I could proceed further.
After some time, I've decided to check why this function was missing?
Quick search showed that function is created by script ?\demo\schema\order_entry\xdbUtilities.sql
Strange, well documented function is created only when you install demo schemas? Seems that there should be another explanation.
Then I've found that in documentation this function has 2 mandatory attributes, while my code has only one attribute. So there are 2 versions of XMLRoot function:

1. SQL function; see documentation
2. Simplified version created by demo in XDB schema - this version can be also used in PL/SQL

Conclusion: my original code should look like that:

SQL> select XMLRoot(xmltype('<a>a</a>'), version '1.0', standalone yes)
2 from dual;

XMLROOT(XMLTYPE('<A>A</A>'),VERSION'1.0',STANDALONEYES)
------------------------------------------------------------------------

<?xml version="1.0" standalone="yes"?>
<a>a</a>

This can run without XMLROOT function in XDB schema.

Hope this will help someone to save some time.
Cheers,Paweł

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