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OLTP Compression, Drop Column, Partition Exchange

With Basic Compression, you cannot drop a column. But with Basic Compression, you can set as unused. With OLTP Compression, on the face of it, you can drop a column. But this is a lie/misdirection. In reality, the dropped column is just renamed. We see the column is not dropped but hidden: Note 1. The […]


An example of sucking data into a table over a db link using DBMS_PARALLEL_EXECUTE. This particular example is based on something I needed to do in the real world, copying data from one database into another over a db link. Datapump is not available to me. Tables in question happen to be partitioned by a […]

Determining Deterministic I – Introduction

There have been a couple of threads recently on the Oracle forums about deterministic functions and the performance benefits thereof. These keep nagging me that I have been meaning to write something up about this DETERMINISTIC assertion and to also investigate a couple of aspects of this further. Put simply, the DETERMINISTIC keyword asserts that […]