DUPLICATE Database using Backup of a Database

If you want to create a duplicate database from a live/active database, you can follow this article. But if you want to DUPLICATE a database using backup of another database, you can use following steps. I am creating new database with a different name using DUPLICATE command, or you may want to retain same name for the database while duplicating.

Configuring OEM Express Control

Starting 12c, OEM Database Control has been replaced by OEM Database Express. OEM Express configuration is very simple as compared to previous OEM Database Control. Following is the method to configure OEM Express. OEM Express Database is configured separately for container database and each pluggable database. Method is same; you just need to set current container to pluggable database for which you want to configure the OEM, and execute the steps as explained bellow.

Calculating ASM diskgroup Usable Size

Sometimes sizing information of an ASM diskgroup returned by “lsdg” command from “asmcmd” prompt (similar information is also available under v$asm_diskgroup view) leaves DBAs perplexed. Sizing information and usable space for diskgroups with EXTERNAL REDUNDANCY is quite easy to understand, but when it comes to NORMAL or HIGH redundancy diskgroups, it is not very straightforward. Here I would explain ASM diskgroup space calculation in detail to make it easier to understand. Before I explain how to calculate usable space in an ASM diskgroup, some useful information to note is as follows