|Oracle® Database Reference
12c Release 1 (12.1)
|PDF · Mobi · ePub|
|Default value||5 MB to 32 MB, depending on the size of the SGA, CPU count, and whether the operating system is 32-bit or 64-bit|
|Range of values||2 MB to 64 MB (32-bit operating systems)
2 MB to 256 MB (64-bit operating systems)
LOG_BUFFER specifies the amount of memory (in bytes) that Oracle uses when buffering redo entries to a redo log file. Redo log entries contain a record of the changes that have been made to the database block buffers. The LGWR process writes redo log entries from the log buffer to a redo log file.
The log buffer size depends on the number of redo strands in the system. One redo strand is allocated for every 16 CPUs and has a default size of 2 MB. Oracle allocates a minimum of 2 redo strands per instance. When the log buffer size is not specified, any remaining memory in the redo granules is given to the log buffer.
Your operating system-specific Oracle documentation for the default value and range of values
Oracle Streams Replication Administrator's Guide for information on using this parameter in an Oracle Streams environment
Oracle Database Performance Tuning Guide for information on resizing the redo log buffer using this parameter