Tag Archives: pdb

Duplicate PDB from active database, ASM, and OMF

Starting with 18c is possible to duplicate one PDB from an active database. This is a cool feature that helps a lot in daily activities. But recently I got one error when the destination is using ASM, and the files (of course) are managed using OMF. The solution is simple and is related to a bug that is affecting the 18c, 19c, and 21c versions.

Duplicating pluggable databases can be done for a long time and have some rules. But the duplicate PDB from an active database to a new CDB helps a lot because everything can be done online. We don’t need to create an intermediate CDB to export this PDB doing the unplug/plug, or cloning the source locally to read-only PDB and create a new one using dblink, or even using rman backups.

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RMAN, Allocate channel, CDB, and CLOSE: bug

Allocate channel for RMAN is used in various scenarios, most of the time is useful when you use tape as device type or you need to use some kind of format. The way to do the allocation not changed since a long time ago, but when you run the database in container mode you can hit a bug that turns your channel unusable. I will show you the bug and how to avoid it with a simple trick.

This bug hit every version since 12 and I discovered it last year when testing some scenarios, but I was able to test and post just recently. It just occurs for CDB databases and exists just one one-off solution published for 12.2. But there is one workaround more useful and works for every version.

The most interesting part is that everything that we made until now when allocate channel will not work. You can search in all doc available for allocate channel since 9i until 19c the first thing that you made after open the run{} is allocate channel. This is the default and recommended in the docs: for 19c, 18c, and 9i.

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