Join a discussion on both explain plans and execution plans in Oracle SQL. How to read them, we will look at which step is first and how the steps interact. We will explain the different steps found in a plan and what they do. What at the attributes of a plan and which of these are important when optimizing a query? Is it always about time or are there other statistics that are important? We will then talk about some fundamental optimization skills to make an execution plan better, faster, and stronger. Is a full table scan always a bad thing? Why isn’t the optimizer using an index? There are several types of index scans, what do they do?
Highlights include:
0:03:20 – Statistics
0:12:00 – Skew
0:15:10 – Execution and explain plans
0:24:05 – Reading plans
0:30:25 – Reading plan basics
0:39:50 – Joins
1:01:30 – Cost
1:07:45 – Finding the problem
1:15:35 – Indexes
1:20:25 – Predicates
1:23:25 – Common table expressions
1:33:15 – Summary
