Friday, August 1, 2014

Parallel Execution Skew - Summary

I've published the final part of my video tutorial and the final part of my mini series "Parallel Execution Skew" at concluding what I planned to publish on the topic of Parallel Execution Skew.

Anyone regularly using Parallel Execution and/or relying on Parallel Execution for important, time critical processing should know this stuff. In my experience however almost no-one does, and therefore misses possibly huge opportunities for optimizing Parallel Execution performance.

Since all this was published over a longer period of time this post therefore is a summary with pointers to the material.

If you want to get an idea what the material is about, the following video summarizes the content:

Parallel Execution Skew in less than four minutes

Video Tutorial "Analysing Parallel Execution Skew":

Part 1: Introduction
Part 2: DFOs and DFO Trees
Part 3: Without Diagnostics / Tuning Pack license
Part 4: Using Diagnostics / Tuning Pack license

"Parallel Execution Skew" series at

Part 1: Introduction
Part 2: Demonstrating Skew
Part 3: 12c Hybrid Hash Distribution With Skew Detection
Part 4: Addressing Skew Using Manual Rewrites
Part 5: Skew Caused By Outer Joins