The log buffer in database systems is appended to the log file on disk when full or under specific conditions to ensure data integrity and support database recovery procedures.
When the log buffer is filled, or when certain other conditions occur, the log buffer is appended to the end of the log file on disk.
In database management systems, log buffers temporarily store transaction logs before they are written to disk. The process ensures data integrity and helps in database recovery in case of a system crash. The log buffer is limited in size, and when it becomes full, its contents are flushed to a log file that is a permanent storage location on disk. Additionally, events such as a transaction commit, a system checkpoint, or the buffer being full, can trigger the flushing of the log buffer to the log file. This operation is crucial for maintaining a consistent state of the database by keeping a record of all transactions that modify the database.
The management and proper handling of the log buffer are essential for database reliability and recovery processes within a database management system.