Mview Complete Refresh and Atomic_refresh parameter

This post discusses issue faced by me while working on Materialized view (mview) creation at new site(database). Starting Oracle 10g, how atomic_refresh works with complete refresh has undergone a change. Atomic_refresh parameter is to allow either all of the tasks of a transaction are performed or none of them (Atomicity). If set to TRUE, then…

CleanUp Temporary Segments Occupying Permanent Tablespace

There are situations when we see “temporary segments” in permanent tablespaces hanging around and not getting cleaned up. These temporary segments in permanent tablespace can be created by DDL operations like CTAS and “alter index..rebuild” because the new object is created as a temporary segment in the target tablespace and when the DDL action finishes…

Index Access best approach?? Not Always…

There is a common misconception that Index access is the best access method for query execution. This approach leads to people concentrate on removing Full Table Scans (FTS) from the Query execution plan. I recently worked on a performance tuning issue where I found such scenario. Basically customer was trying to generate report for 3…