Tuning the Redo Log Buffer - iDevelopment.info

The user thread waits until the reserved range of lsn values maps to free space in the log buffer, which is true when: end_lsn - log.write_lsn <= log.buf_size Remarks The waiting is performed by a call to log_write_up_to(end_lsn - log.buf_size), which has a loop with short sleeps. We assume that it is unlikely that the waiting is actually needed. Tuning for Oracle Log Buffer Space Waits Dec 10, 2013 Tuning the Oracle Log Buffer Size - Dell Community

Jan 05, 2016

Description: This wait type is when a thread is waiting for a free log buffer in the log cache, so the current log block that is in the process of ending (because it reached the maximum 60KB size or because a transaction wrote an LOP_COMMIT_XACT log record) can be copied into the log cache and then subsequently written to disk. (Books Online description: “Occurs when a task is waiting for MySQL: Redo log buffer The user thread waits until the reserved range of lsn values maps to free space in the log buffer, which is true when: end_lsn - log.write_lsn <= log.buf_size Remarks The waiting is performed by a call to log_write_up_to(end_lsn - log.buf_size), which has a loop with short sleeps. We assume that it is unlikely that the waiting is actually needed. Tuning for Oracle Log Buffer Space Waits

If the log buffer is too small, then log buffer space waits will be seen during high redo generation. And LGWR may not begin to write redo entries to redo log file until it reaches the threshold. This may cause serious performance problem. Ideally, the log buffer should be …

Oracle log buffer space