While
unused block compression lessens the number of blocks that are written to the
backup, binary compression can be used to algorithmically compact the data that
is written. There are two compression algorithms available: ZLIB and BZIP2.
ZLIB is faster than BZIP2, and also has a smaller compression ratio. ZLIB is
the default. ZLIB can be used only if the COMPATIBLE initialization parameter
is set to at least 11.1.0.
You do not
have to perform any additional steps when restoring a compressed backup. Note
though, that compression and decompression operations require CPU resources.
So, of course, both creating and restoring a compressed backup will probably
take longer and require more system resources.
When
choosing an algorithm, consider your disk space in addition to your dynamic
system resources such as CPU and memory.
