COMP_SYNC 2: exclude surrogate keys

At the recent ILOUG conference, Sabine Heimsath asked how to compare two tables where the surrogate keys do not match. Here's how, using my revised comparison package.

COMP_SYNC 1: a new table compare/sync package

I have been meaning to update my COMPARE_SYNC package for some time. I want to change the interface and the functionality a bit, so I am leaving the existing package alone and creating a new one called COMP_SYNC.

Techniques for Comparing Tables

In my "Advanced Row Pattern Matching" presentation, I demonstrate using MATCH_RECOGNIZE to compare tables. Kim Berg Hansen asked me to compare this technique with others. I did some quick tests and here are the results with some comments.

My #ilOUG18 presentations

I just finished presenting at the Israeli OUG conference. The conference was a great experience, from the Sunday visit of Jerusalem to the two days of presentations. Thanks to the organizers for inviting me and taking great care of everyone! Slideshare does not allow me to upload a new version of my slides, so here […]

My #ukoug_tech17 presentation on Advanced Row Pattern Matching

I just finished presenting on this topic, had a great time and got some memorable praise. Thanks again to all who attended for your benevolent attention – and your correct answers to my questions! As promised, the absolutely freshest copy of the slides is now on the Conference website and on slideshare: Advanced row pattern […]

ODC Appreciation Day: Mike Hichwa’s team #ThanksODC

I don't know Oracle's internal organization, but I get the impression that people like Joel Kallman, Jeff Smith and Kris Rice work for or with Mike Hichwa. By naming him, I get to show appreciation for a bunch of technologies, and for the people behind them.

Optimistic Locking 6: which ORA_ROWSCN?

Continuing my series on using ORA_ROWSCN to achieve optimistic locking, let’s zoom in on ORA_ROWSCN itself. I've been asking myself this question:
  • ORA_ROWSCN can be maintained at the block level or the row level. What is the difference and which one should we use?

Optimistic Locking 5: “Read-consistent” SCN

Continuing my series on using ORA_ROWSCN to achieve optimistic locking, let's zoom in on the query API and the "read-consistent" SCN of the data it returns. I've been asking myself these questions:
  • How do we get read-consistent data in the query API if it does more than one SELECT?
  • How do we know the exact value of the "read-consistent" SCN?

Optimistic Locking 4: the Good

After discussing lost updates, the SCN and my theoretical use case, here is my idea for doing SCN-based optimistic locking. I'm going to simplify and emphasize the advantages here; limitations and gruesome details will come later.