How do you compare a rewritten query to its original version? Most of the time I just run a MINUS operation on the original and new query. Actually I execute two. Old query (A) MINUS New query (B) and vice versa (B) MINUS (A). Both should result in no rows. That way I thought I […]
Read moreChange UUIDs in VirtualBox
If you are anything like me you will have multiple virtualboxes running on your system. Sometimes you might want to run a copy of a virtualbox for different purposes. Like running an Oracle 11 Devdays instance as test environment but also running the same vbox for customer testing. If you copy the vbox and try […]
Read moreConnecting PL/SQL Developer
In SQL Developer you have a lot of options when connecting to the database. You can use the TNS entries defined but you can also give the hostname, port and SID or Servicename for instance. PL/SQL Developer doesn’t supply these options, but you can still use them…
Read moreHow can we use Oracle to deduplicate our data
Dear Patrick, We have gone through a merger at our company where we are trying to merge the databases. The problem now is that we have duplicate records in our tables. We can of course go through all the records by hand and check if they exist twice. Another option is to build an application […]
Read moreOTN Appreciation Day : Prebuilt Developer VMs
I learnt a lot from the entire Oracle Technology Network and I still do. One of the best features of OTN these days, IMHO, is the ability to download prebuilt Virtual Machines. Since I am a developer and not an administrator, I don’t like to be bothered with stuff like how much disk space do […]
Read moreHow can we add custom code to existing triggers?
Dear Patrick, We have bought an application that runs on an Oracle database. There are triggers defined on the tables, but we want to add our own code to these triggers, but we don’t have access to the source code. What is the approach we should follow to accomplish this? Collin Bratforth
Read moreWhat is overloading and how and when do I use it
Dear Patrick, Recently I heard someone talk about overloading in Java. What is it, is it possible in PL/SQL and if so, how would I use it? Ramesh Cumar
Read moreWhen would you use a normal table function?
Dear Patrick, Last year I did a presentation on table functions at KScope. One of the questions I got was: ‘If pipelined table functions provide their results faster, why would you want to use a normal table function?’ I couldn’t come up with the answer then, maybe you can help? Erik van Roon
Read moreWhat’s the difference between SEMI-JOIN and ANTI-JOIN?
Dear Patrick, What is an ANTI-JOIN? And what is the difference between the SEMI-JOIN and the ANTI-JOIN? Lillian Sturdey
Read moreWhat is the difference between NVL and COALESCE?
Dear Patrick, Could you tell me what the difference is between NVL and COALESCE? Kindest regards, Paul McCurdey
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