Session Number: 1198
Track: 5-Data Warehousing and SQL
Session Type: Best Practices, Tips & Tricks
Primary Presenter: Kerry Osborne [DBA - Accenture]
Time: Jan 26, 2016 (02:40 PM - 03:30 PM)
Session level: Intermediate
Abstract (250 words or less):
Oracle specialists often find themselves in the unenviable position of being asked to make things better without touching the code. Oracle has provided various mechanisms for accomplishing this over the years, including Outlines, SQL Profiles, and SQL Baselines. These techniques provide laser-like specificity by limiting their effect to a single statement. While these constructs are extremely powerful, they are not well documented and, therefore, not particularly well understood. Also, they suffer from some quirkiness. For example, despite what the documentation implies regarding Outlines locking execution plans, there are situations where creating an Outline on an existing statement will actually cause the plan to change. This quirk is not limited to the older Outline construct. It has been carried forward to the newer SQL Profiles and SQL Baselines as well.