1 说明
从12.2开始，支持并行创建pdb。毫无疑问会加快PDB的创建，当数据库版本是12.2.0或更高，默认Oracle会自动选择并行度。
The PARALLEL clause of the CREATE PLUGGABLE DATABASE statement specifies whether to use parallel execution servers during PDB creation and, optionally, the degree of parallelism.
You can use this clause to make the creation of PDBs faster by using more than one parallel execution server to copy the new PDB’s data files to a new location. When the compatibility level of the CDB is 12.2.0 or higher, the CDB chooses the degree of parallelism to use for PDB creation by default. Alternatively, you can specify the desired degree of parallelism in the clause, but the CDB can ignore the suggestion, depending on the current database load and the number of available parallel execution servers.
CDB根据当前的负载情况，决定是否使用并行，哪怕是指定了并行度。
When a value of 0 or 1 is specified, the CDB does not parallelize the creation of the PDB. Specifying 0 or 1 can result in longer PDB creation time.
Use this clause only when you are creating a PDB from the CDB seed or an application seed, or when you are cloning a PDB.
注意：只有当通过CDB seed,应用程序 seed或者通过克隆一个PDB来创建PDB时，才可以使用PARALLEL参数。
语法:
create pluggable database sihong admin user cndba identified by cndba
file_name_convert=('/u01/app/oracle/oradata/orcl/pdbseed/','/u01/app/oracle/oradata/orcl/sihong/') PARALLEL 4