Oracle Database 11g Advanced Compression introduced several set of options. Oracle also introduced compression for network traffic. With the option of advanced compression, the primary database will send the redo data and may be transported in a compressed format to reduce network consumption on the standby database. In the earlier releases, redo has been compressed over the network using third-party utilities such as WAN accelerators and other tools. To use the compression feature of Oracle, you must have purchased the license of Oracle 11g advanced compression. By licensing this option, archive gaps can be resolved up to three times faster, thereby providing better protection, and network utilization can be controlled by reducing the redo transfer time. Compression is supported for all the redo transport modes such SYNC and ASYNC and for the transport methods such as ARCH and LGWR to resolve gaps of Data Guard. These are compatible with all the protection modes—Maximum Performance, Maximum Protection, and Maximum Availability.

Before implementing compression, ensure that sufficient CPU resources are available and the database redo rate is higher than the available network bandwidth to take advantage of compression. This feature can be used in 11gR1 by setting the undocumented parameter _REDO_TRANSPORT_COMPRESS_ALL to TRUE along with the attribute COMPRESSION=ENABLE in LOG_ARCHIVE_DEST_n. From 11gR2 onwards, this parameter is no longer required.