Skip to main content

Intermittent ORA-06502 error when running APEX 5 on 12c

We upgraded our environment from 11.2 to 12c last week. This week we noticed an error in one of our APEX pages, a rather simple form for entering data. Nothing fancy, nothing spectacular - only a spectacular error when you tried to edit a record. 
Running the page in debug mode (even on LEVEL9) wasn't very helpful as you can see below (10 points who immediately spots the error!).
The error didn't occur for all records. It seems that a long(er) Code and Description field on the page resulted in an error more frequently. Also fiddling with a couple of the checkbox fields on the page had an effect.
So I asked Twitter for help. And within a few minutes I got all kinds of tips and advice. But especially one, from Peter Raganitsch was spot on. He suggested, looking at the debug output above, to take a look at the #CLOSE# position in the template. .
My buttons are positioned in that #CLOSE# position, so I took a closer look at those. There were three that passed the Id, Code and Description to other pages as a parameter. So ... the longer the description ... the longer the generated URL would be. And as one of the checkboxes would toggle the availability of one of the buttons, that would also have an effect on the total length of the URL's in that region position. 
So I changed a little code, to pass only the Id's to the other pages (and add a select statement there to (re)fetch the Code and Description. And since then ... it runs as a breeze.

Very weird though this was not on issue on 11.2, but is on 12c....

So what causes this issue, what is the difference?
The answer is: the checksum!

If I create a Report and a Form on DEMO_CUSTOMERS, using the CUSTOMER_ID as the Primary Key, the URL has this checksum on 11.2 : " &cs=3Fqn7QOYkP-TDSLkssvzU7i7QL1E "
On 12c however, the checksum is :" &cs=36Drf3ULxGXswIlT5btBujofcmgwdjJsr-luSfpLjSMpXP71DILliWBz31qkpRJHyPj2RS8iLce5qNkXSSeGbvQ "
And that was probably enough extra length to pass a certain varchar2(<some number here>) in the APEX code that generates the page output....


Post a Comment

Popular posts from this blog

Showing a success message after closing a modal dialog

APEX 5 comes with Modal Dialogs out of the box. Very neat. Especially for adding and changing data. And to minimise the number of time a user has to click, it could be useful to add a "Close Dialog" process after the actual data processing. When the data processing fails, the Dialog stays on top showing the error. When data processing runs fine, the Dialog is closed ... without any confirmation. And this might be scary for a shaky user.

So how can we provide the user some feedback? On Page 4 of the Sample Dialog Application you can see one solution: up on a Dialog Closed Event on the parent page it does a redirect to refresh the parent page appending the success message of the "Close Dialog" process. This has two drawbacks. First, it probably refreshes more than necessary. And second, if you're using multiple layers of dialogs (dialogs that open other dialogs) the message appears in the "parent dialog".
As an alternative you could follow these steps: 1…

It's happening again ... running for the ODTUG Board of Directors 😉

For the third time in a row I'll be running for ODTUG's Board of Directors. But after ending as a runner up twice, I am sure I'm going to make it this time! But not without your help!

My campaign statement this year is:
I have been attending and presenting at Kscope conferences since 2007. This not only resulted in a vast amount of knowledge, but also - and even more important - a huge number of friends from all over the globe.  I want to see ODTUG grow and spread this community feeling even more! 
My experience as an attendee, presenter and content lead has provided the basic foundation to be a director. Next to that, my personality and (global) network will be beneficial to the whole board and organization. 
Since March I have served on the Board of Directors in a limited term for a Director who stepped down due to a career change. This has allowed me to have unique insight of all the things that are going on in and around the ODTUG organization. As the train was already ro…

Consuming a REST Web Service returning JSON in APEX

In APEX you can define a web service that returns XML as below - all declarative, just a few steps through a wizard.


Then generate a report on top of that web service - again just a few clicks through a wizard. The generated query looks like this:
select xtab."customerName"      , xtab."customerId"   from apex_collections c,            XMLTable('/Response/S_getCustomerListTableArray/S_getCustomerListArrayItem' passing xmltype001             COLUMNS "customerName" PATH 'customerName'                   , "customerId"   PATH 'customerId'           ) xtab  where c.collection_name = 'CUSTOMERLIST'
So the result of the web service is stored in an XMLTYPE column. And it's easy to spot where you're definitions for the Response XPath and Output Parameters are used.
But what if your web service returns JSON - as more and more web services will do so? If you switch the Output Format of the web service definition to JSON, th…