Below tables contains contant you need to consider while planning for a CDB.
| Action | Considerations for a CDB | Additional Information |
|---|---|---|
|
Plan the tables and indexes for the pluggable databases (PDBs) and estimate the amount of space they will require. |
In a CDB, most user data is in the PDBs. The root contains no user data or minimal user data. Plan for the PDBs that will be part of the CDB. The disk storage space requirement for a CDB is the space required for the Oracle Database installation plus the sum of the space requirements for all of the PDBs that will be part of the CDB. A CDB can contain up to 253 PDBs, including the seed. |
Part II, "Oracle Database Structure and Storage" |
|
Plan the layout of the underlying operating system files your CDB will comprise. |
There are separate data files for the root, the seed, and each PDB. There is one redo log for a single-instance CDB, or one redo log for each instance of an Oracle Real Application Clusters (Oracle RAC) CDB. Also, for Oracle RAC, all data files and redo log files must be on shared storage. |
Chapter 17, "Using Oracle Managed Files" Oracle Automatic Storage Management Administrator‘s Guide Oracle Database Performance Tuning Guide Oracle Database Backup and Recovery User‘s Guide Oracle Grid Infrastructure Installation Guide for information about configuring storage for Oracle RAC Your Oracle operating system–specific documentation, including the appropriate Oracle Database installation guide. |
|
Plan for the number of background processes that will be required by the CDB. |
There is one set of background processes shared by the root and all PDBs. |
"Specifying the Maximum Number of Processes" |
|
Select the global database name, which is the name and location of the CDB within the network structure, and create the global database name for the root by setting both the DB_NAME and DB_DOMAIN initialization parameters.
|
The global database name of the root is the global database name of the CDB. The global database name of a PDB is defined by the PDB name and the |
"Determining the Global Database Name" |
|
Familiarize yourself with the initialization parameters that can be included in an initialization parameter file. Become familiar with the concept and operation of a server parameter file (SPFILE). An SPFILE file lets you store and manage your initialization parameters persistently in a server-side disk file. |
A CDB uses a single SPFILE or a single text initialization parameter file (PFILE). Values of initialization parameters set for the root can be inherited by PDBs. You can set some initialization parameters for a PDB by using the ALTERSYSTEM statement.(这样更改的Parameter会对只对该PDB有效吗？重启后还会保持吗？)
The root must be the current container when you operate on an SPFILE. The user who creates or modifies the SPFILE must be a common user with To create a CDB, the |
"Specifying Initialization Parameters" "Using the ALTER SYSTEM SET Statement in a CDB" "Listing the Initialization Parameters That Are Modifiable in PDBs" |
|
Select the character set. |
All of the PDBs in the CDB use this character set. When selecting the database character set for the CDB, you must consider the current character sets of the databases that you want to consolidate (plug) into this CDB. |
Oracle Database Globalization Support Guide |
|
Consider which time zones your CDB must support. |
You can set the time zones for the entire CDB (including all PDBs). You can also set the time zones individually for each PDB. |
"Specifying the Database Time Zone and Time Zone File" |
|
Select the standard database block size. This is specified at CDB creation by the DB_BLOCK_SIZEinitialization parameter and cannot be changed after the CDB is created.
|
The standard block size applies to the entire CDB. |
"Specifying Database Block Sizes" |
|
If you plan to store online redo log files on disks with a 4K byte sector size, then determine whether you must manually specify redo log block size. Also, develop a backup and recovery strategy to protect the CDB from failure. |
There is a single redo log and a single control file for an entire CDB. |
"Planning the Block Size of Redo Log Files" Chapter 11, "Managing the Redo Log" Chapter 12, "Managing Archived Redo Log Files" |
|
Determine the appropriate initial sizing for the SYSAUX tablespace.
|
There is a separate SYSAUX tablespace for the root and for each PDB.
|
"About the SYSAUX Tablespace" |
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Plan to use a default tablespace for non- SYSTEMusers to prevent inadvertently saving database objects in the SYSTEM tablespace.
|
You can specify a separate default tablespace for the root and for each PDB. Also, there is a separate SYSTEMtablespace for the root and for each PDB.
|
"Creating a Default Permanent Tablespace" |
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Plan to use one or more default temporary tablespaces. |
There is a default temporary tablespace for the entire CDB. You optionally can create additional temporary tablespaces for use by individual PDBs. |
"Creating a Default Temporary Tablespace" |
|
Plan to use an undo tablespace to manage your undo data. |
There is one active undo tablespace for a single-instance CDB. For an Oracle RAC CDB, there is one active undo tablespace for each instance. Only a common user who has the appropriate privileges and whose current container is the root can create an undo tablespace. In a CDB, the Undo tablespaces are visible in static data dictionary views and dynamic performance (V$) views when the current container is the root. Undo tablespaces are visible only in dynamic performance views when the current container is a PDB. Oracle Database silently ignores undo tablespace and rollback segment operations when the current container is a PDB. |
Chapter 16, "Managing Undo" |
|
Plan for the database services required to meet the needs of your applications. |
The root and each PDB might require several services. You can create services for the root or for individual PDBs. Therefore, ensure that the planned number of services do not exceed the database service limit. Database services have an optional When you create a PDB, a new default service for the PDB is created automatically. The service has the same name as the PDB. You cannot manage this service with the SRVCTL utility. However, you can create user-defined services and customize them for your applications. |
"Managing Application Workloads with Database Services" "Managing Services Associated with PDBs" "SRVCTL Command Reference for Oracle Restart" for information about using the SRVCTL utility with a single-instance database Oracle Real Application Clusters Administration and Deployment Guide for information about using the SRVCTL utility with an Oracle RAC database |
|
Familiarize yourself with the principles and options of starting up and shutting down an instance and mounting and opening a CDB. |
In a CDB, the root and all of the PDBs share a single instance, or, when using Oracle RAC, multiple concurrent database instances. You start up and shut down an entire CDB, not individual PDBs. However, when the CDB is open, you can change the open mode of an individual PDB by using the ALTER PLUGGABLE DATABASE statement, the SQL*Plus STARTUP command, and the SQL*Plus SHUTDOWNcommand.
|
"Starting Up a Database" "Modifying the Open Mode of PDBs" "Modifying a PDB with the ALTER PLUGGABLE DATABASE Statement" |
|
If you plan to use Oracle RAC, then plan for an Oracle RAC environment. |
The Oracle RAC documentation describes special considerations for a CDB in an Oracle RAC environment. |
See your platform-specific Oracle RAC installation guide for information about creating a CDB in an Oracle RAC environment. Oracle Real Application Clusters Administration and Deployment Guide |
|
Avoid unsupported features. |
The Oracle Database Readme includes a list of Oracle Database features that are currently not supported in a CDB. If you must use one or more of these features, then create a non-CDB. |
Chapter 2, "Creating and Configuring an Oracle Database" |
Oracle Multitenant Environment (三) Plan for a cdb