PDB

Upgrade PDBs – One at a Time via unplug/plug/upgrade

Basically there are two techniques to upgrade an Oracle Multitenant environment:Everything at Once and One (or many) at a Time. This blog post describes the case how to Upgrade PDBs – One at a Time via unplug/plug/upgrade. I will describe all necessary steps. During some presentations, discussions etc people were left with the impression that it will be a very simple approach to unplug one or many PDBs from a CDB in lets say Oracle 12.1.0.1 and plug it into an Oracle 12.1.0.2 Container Database. Bingo, upgraded!

Well, unfortunately this is not true. In fact it … [ Read more ]

More than one PDB in the same directory?

Can you create more than one pluggable database (PDB) within the same directory?
And how does the file naming work? Considering the fact each PDB’s SYSTEM tablespace will be named system01.dbf by default the question is not trivial.

This question got asked by a customer during one of the workshops in Switzerland last week. And the solution is straight forward. Thanks to Roy for trying it out yesterday at 170 km/h on our way back from Stuttgart 🙂

Thanks 🙂

-Mike

Additional information:

Within ASM with OMF the file structure looks like this:

select con_id, substr(file_name,1,90),tablespace_name from cdb_data_files order by 
[ Read more ]

Starting up 252 PDBs automatically?

In my recent posting I have explained the startup of many PDBs at the same time.

But once you startup the container database CDB$ROOT the PDBs will stay in MOUNT status. So how do you start them during CDB$ROOT startup (or immediately afterwards) in an automatic fashion?

A startup trigger will do this job.

CREATE OR REPLACE TRIGGER startup_all_pdbs
AFTER STARTUP ON DATABASE

BEGIN

EXECUTE IMMEDIATE ‘ALTER PLUGGABLE DATABASE ALL OPEN’;

END;

/

And of course you can use the EXCEPT command option to exclude one or more PDBs from the automatic startup.

CREATE OR REPLACE TRIGGER startup_all_pdbs_except_a_few
AFTER STARTUP
[ Read more ]

Starting up 252 PDBs in Oracle Multitenant

What happens when you start up 252 PDBs (Pluggable Databases) with the Oracle Multitenant Option for the first time?

Interesting question, isn’t it? The expectation would be that this will happen within seconds as the SGA and therefore the shared memory segments are already allocated from within the CDB$ROOT (Container Database). But …

The following happens:
It takes minutes … hours …. In my tiny lab environment with just as little as 20 PDBs due to space constraints it takes over 30 minutes to startup 21 PDBs. Takashi Ikeda from Fujitsu Hokoriku Systems who did a great demo with the … [ Read more ]