SELECT statement in combination of ORDER BY or GROUP BY clause performs SORT operation which we all accept from the concepts of oracle architecture. Sort area in MEMORY is one of the areas of PGA in dedicated server architecture or will be part of SGA in shared server architecture. We all believe that sort in […]
After gaining theoretical knowledge from the Oracle documents or from Oracle university training every DBA will be under presumption that only DML operations in the database generates REDO segments. But practically it is not completely true. On few occasions you can identify that SELECT statements generates REDO segments in the instance. Next question you might […]
There are multiple ways to capture blocking sessions in oracle database. 1. A full query to get list of blocking sessions with BLOCKER, WAITER and OBJECT being blocked:It works on Single Instance and RAC set-up as well. 2. A simple query to find out blocking in the database: 3. To get limited information on blocking […]
