Author Archives

Testing solution to MERGE with sequence NEXTVAL

In my last blogpost (“Strange behavior in MERGE with sequence NEXTVAL”) I had a link to article written by Bob Jankovsky. In this article is suggest solving the issue with MERGE and nextvalue by returning the nextvalue from a function. In this blogpost I’ll do some tests and see how this behaves (regarding timings).

Strange behavior in MERGE with sequence NEXTVAL

Today we learned the following: “When using a sequence in a MERGE statement, the nextvalue is generated for all rows both updated and inserted (hence all rows in the source).” Our initial reaction was that this must be a bug, but is it really?

Scripts: Tanel Poder´s TPT script out on GitHub

Tanel Poder have uploaded his TPT script to GitHub. If you have never looked as his script I highly recommend spending some time on them. You’ll find them at:

Java: JDBC roundtrips are expensive

SQL Daily just tweeted about the fact that JDBC roundtrips are expensive. This is something many developers either forget or do not know. I have seen so many chatty applications killing the application performance, and the database performance. Toon Koppelaars have performed some excellent presentations showing this. Lukas Eder have also written some nice articles […]

Java: Nice article about Java, Time and Dates

I really enjoyed the following article about Java, Time and Dates: From the article: An introduction to java.time Time is a complex topic. Many programmers are unfamiliar with the difficulties and common bugs associated with time. This has in the past lead to time APIs that allowed “sloppy” code which can lead to bugs in […]

PLSQL: Using Datapump API with filter on multiple tables

The developers in one of the teams I work within wanted to export the tables in a schema with limited number of rows. This could of course be done by running  expdp command line.  But this time we needed to find the last x numbers of primary keys in one of the central tables and […]

Nice blog about DBMS_METADATA from Alex Nuijten

This blog post has been laying in my TO_READ folder for a long time. Finally found some time to catch up, and I especially liked the little piece of PL/SQL for remapping the schema.

OOW16 – Are we failing or will performance rise?

The last session I attended at OpenWorld 2016 was “Thinking Clearly About Database Application Architecture”. A panel discussion with Toon Koppelaars, Cary Millsap, Gerald Venzl, Bryn Llewellyn and Connor Mcdonald. The panelists promotes that the business logic should be moved into the database, and implemented using PL/SQL. And yes – I do get the message, but I just […]