twp-upgrade-oracle-database-19c
Method 1: DBUA or Command-Line Upgrades
The easiest way to move up to Oracle Database 19c is to upgrade your existing database using either DBUA or the command-line upgrade scripts. These are two variants of the same method, differing primarily in their user interfaces. Because these methods act on your database without creating a copy or a new instance, this is sometimes referred to as upgrading “in place.”
DATABASE UPGRADE ASSISTANT
Database Upgrade Assistant is a graphical user interface (GUI) that guides you through the database upgrade process and presents a series of screens that allow you to specify options for your database upgrade. During the upgrade process, DBUA invokes the same scripts used for the command-line upgrade. It also performs pre-upgrade validation steps and can automate post-upgrade tasks. Using DBUA can significantly reduce the amount of manual effort required for a database upgrade but offers less flexibility than the command-line upgrade. DBUA is fully described in Oracle Database Upgrade Guide.
Method 2: Full Transportable Export/Import or Transportable Tablespaces
Transportable tablespaces allows you to copy a set of tablespaces from one database to another. This can be much faster than exporting and importing data from those tablespaces because the tablespaces are copied as physical files without the need to interpret the logical entities, such as rows or indexes, contained within those files. However, in addition to copying the tablespaces, metadata describing the objects within the source database must be moved to the new database by Data Pump export/import.
Transported tablespaces can be copied to another database that may be on a different operating system platform or running a different version of Oracle Database software. This makes transportable tablespaces a relatively fast way to migrate and upgrade a database in a single operation. In the past, the tradeoff for this speed is that transportable tablespaces could be fairly complicated, because the user was responsible for moving metadata such as procedures, packages, constraints, and so on. Starting with Oracle Database 19c, the full transportable export/import feature combines the speed of transportable tablespaces with a much easier process for transporting metadata and data from installed database options.
FULL TRANSPORTABLE EXPORT/IMPORT
Full transportable export/import is a feature of Oracle Database that makes it easy to move an entire database using the transportable tablespaces feature. It automates the process of moving metadata and can move user data that resides in non-transportable tablespaces such as SYSAUX and SYSTEM. In addition, full transportable export/import can transport encrypted tablespaces.
Full transportable export/import moves metadata using either dump files or a database link. This combination of speed and simplicity makes full transportable export/import a good choice for many migration scenarios. The detailed steps for using full transportable export/import are described in the Oracle white paper, “Oracle Database 12c: Full Transportable Export/Import.” The overall process for full transportable export/import has not changed for Oracle Database 19c.
Method 3: Oracle Data Pump Export/Import
Oracle Data Pump provides high-speed movement of data and metadata within and between Oracle databases. Because they are extremely flexible and easy to use, the Oracle Data Pump export (expdp) and import (impdp) utilities are commonly used to migrate tables, schemas, and databases to new hardware servers, to different operating system platforms, and to new releases of Oracle Database software.
Oracle Data Pump can write data to dump files on disk, or it can transfer data from the source database to the destination directly over the network. When the data is imported, it can be transformed to match the characteristics of the destination database. Some interesting ways in which a database can be transformed upon import include migrating to a new character set, implementing encryption or compression, changing BasicFiles LOBs to SecureFiles LOBs, or changing the partitioning of tables in the database.
DATA PUMP EXPORT/IMPORT WITH DUMP FILES
Exporting data to a dump file has been the most common way to move data between databases for many years. Data Pump export chooses the best available method to extract data from the source database into flat files, and Data Pump import makes a similar decision to read from dump files and insert data into the destination database.
The biggest advantages of exporting to dump files are that you retain a persistent copy of the data on disk, and that you can take advantage of greater parallelism during the export and import operations. This allows you to reuse the dump files for multiple imports, which can be particularly helpful when you need to test or tune your import of your source database. Another case in which exporting to dump files can be helpful is when the network between the source and destinations is relatively slow. In such cases it may be faster to physically disconnect a disk from the source system and connect it to the destination, compared to copying data over the network.
