You’ve probably heard sayings like “sometimes things aren’t always what they seem” and “people lie”. Well, sometimes execution plans lie. It’s not really by intent, but it is sometimes difficult (or impossible) to represent everything in a query execution tree in nice tabular format like dbms_xplan gives. One of the optimizations that was introduced...
Posts Tagged ‘ Parallel Execution ’
The Core Performance Fundamentals Of Oracle Data Warehousing – Parallel Execution
Leveraging Oracle’s Parallel Execution (PX) in your Oracle data warehouse is probably the most important feature/technology one can use to speed up operations on large data sets. PX is not, however, “go fast” magic pixi dust for any old operation (if thats what you think, you probably don’t understand the parallel...
Oracle Parallel Execution: Interconnect Myths And Misunderstandings
A number of weeks back I had come across a paper/presentation by Riyaj Shamsudeen entitled Battle of the Nodes: RAC Performance Myths (avaiable here). As I was looking through it I saw one example that struck me as very odd (Myth #3 – Interconnect Performance) and I contacted him about it. After further review...