If we need to manage multiple applications' schemas with same name, we can't do it in a single database. We have to go for multiple databases or multiple machines. This will lead to additional costs in terms of memory, CPU usage and administration. In case of Multitenant Container Database(CDB), we can have multiple virtual databases on one physical database. This is similar to virtual machines and these virtual databases/containers are called Pluggable Databases(PDB). The actual physical database that holds all these containers is the CDB.
To use this functionality, you can first create a CDB and then create PDBs. A CDB will have a root container, seed$PDB(template for creating PDB) and multiple PDBs. If you don't need this functionality, you can simply create a non-CDB which we had earlier to Oracle 12c.
The advantage of this feature is that we can host multiple PDBs for various applications on a single machine - on a SINGLE DB INSTANCE. These PDBs behave like independent databases. So we can set different admin constraints for each PDB. And we can also make some top level changes to CDB which all the PDBs can use - for example, adding extra resources or upgrading DB.
Also, all these PDBs are pluggable - that is you can get a non-CDB and plug it as a PDB or plug a PDB from CDB1 to CDB2. For example, to debug a production app in testing environment, you can easily get production data by plugging in the production PDB to testing environment.
To use this functionality, you can first create a CDB and then create PDBs. A CDB will have a root container, seed$PDB(template for creating PDB) and multiple PDBs. If you don't need this functionality, you can simply create a non-CDB which we had earlier to Oracle 12c.
The advantage of this feature is that we can host multiple PDBs for various applications on a single machine - on a SINGLE DB INSTANCE. These PDBs behave like independent databases. So we can set different admin constraints for each PDB. And we can also make some top level changes to CDB which all the PDBs can use - for example, adding extra resources or upgrading DB.
Also, all these PDBs are pluggable - that is you can get a non-CDB and plug it as a PDB or plug a PDB from CDB1 to CDB2. For example, to debug a production app in testing environment, you can easily get production data by plugging in the production PDB to testing environment.
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