By Franck Pachot . As in previous posts (1 and 2) I’m still playing with multitenant dictionary. You may wonder why I’m spending time to do unsupported things that we will never be able to use in real life. Of course, playing with internals is fun 😉 But it’s not only that. We will implement CDB databases (multi-tenant, and single-tenant…
By Franck Pachot . I’ve described Oracle 12c metadata and object links internals in a previous post. But before that, the first time I investigated on it, I made a wrong assumption because I was looking at AUDIT_ACTIONS which is not correctly implemented. That investigation came from a question on dba-village. And recently Ivica Arsov (@IvicaArsov) has made an interesting…
By Franck Pachot . How to migrate from non-CDB to CDB? Of course all known migration methods works. But there is also another solution: upgrade to 12c if necessary and then convert the non-CDB to a PDB. This is done with the noncdb_to_pdb.sql which converts a non-CDB dictionary to a PDB one, with metadata and object links. But do you…
By Franck Pachot . I’ve blogged about multitenant internals at the time when 12.1.0.1 was just released. Something has changed in 12.1.0.2 and blogging about it was in my todo list for a long time. Now the occasion to do it has been triggered by a question on Oracle Forums about CDB_DATA_FILES not showing PDB$SEED datafiles because there is an…
By Franck Pachot . Your datafiles have grown in the past but now you want to reclaim as much space as possible, because you are short on filesystem space, or you want to move some files without moving empty blocks, or your backup size is too large. ALTER DATABASE DATAFILE … RESIZE can reclaim the space at the end of…
By Franck Pachot . Do you remember last year, when 12c arrived with multitenant, David Hueber warned us about the fact that a single PDB can, under certain conditions, generate a complete system downtime? We are beta testers and opened a SR for that. Now one year later the first patchset is out and obviously I checked if the issue…
By Franck Pachot . It’s just a patchset. The delivery that is there to stabilize a release with all the bug fixes. But it comes with a lot of new features as well. And not only the one that has been advertised as the future of the database. It’s a huge release. Let’s have a look at what’s new. First,…
By Franck Pachot . Warning: this is only geek stuff about internals on multitenant database dictionary, metadata, and object links. It has nothing to do with the operations that you can do on your database. Don’t try that in production or you can corrupt the whole dictionary. In 12 multitenant database (aka CDB) we know that each pluggable database is…
