RelationalDBDesign RelationalDBDesign

Managing File Copies   «Prev  Next»
Lesson 7Parallelization of Image Copies
ObjectiveIdentify why and how to parallelize the creation of Image Copies

Parallelization of Image Copies

Earlier, you learned how to make image copies of files in the database and how to allocate multiple channels to enable parallelization for backups. In this lesson, you will put these two concepts together.

Parallel image Copies

To use parallelism when you create a backup set, you simply have to issue multiple allocate commands and run the backup. The scenario is a bit different when you are making image copies.
Recovery Manager can specify only one location for each image file copy created. Because of this limitation, you would issue multiple allocates and then list multiple files in your copy command.
An image copy backup that uses multiple channels would use a Recovery Manager script like this:

run {
 allocate channel c1 type disk;
 allocate channel c2 type disk;
  datafile 'C:\Oracle\DATABASE\  
RCV1ORC1.ORA' to ' D:\backup\RCV1ORC1.ORA', 
datafile 'C:\Oracle\DATABASE\RCVORC1.ORA' 
to ' D:\backup\RCVORC1.ORA'; 
The image copies will be allocated to the number of channels available. The maximum degree of parallelization depends on the number of channels, not the number of files listed in the copy command. For instance, if you were to allocate three channels and specify six files in the copy command, Recovery Manager would run three copy sessions in parallel.
In the next lesson, you will learn about creating operating system image backups.