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
An interesting column in dm_os_buffer_descriptors is the free_space_in_bytes column. This tells us how full each page in the buffer cache is, and therefore provides an indicator of potential wasted space or inefficiency. We can determine the percentage of pages that are taken up by free space, rather than data, for each database on our server: Log Cache Page size - social.msdn.microsoft.com Sep 15, 2010 Monitoring the Redo Log Buffer (Oracle) (SAP Library Allocation retries shows the number of failed attempts to allocate space in the redo log buffer. A value greater than zero normally indicates that the Oracle log writer process (LGWR) could not write redo entries from the buffer to disk (in the online redo log files) immediately, but had to wait for a redo log file switch to perform this action.
Event "log buffer space" in v$system_event and v$session_wait.
log buffer space | Smart way of Technology This entry was posted in Oracle and tagged buffer busy waits, db files sequential read, direct path read, direct path write, enq:tx - row lock contention, library cache pin, log buffer space, log file sync, scattered read on June 7, 2013 by SandeepSingh DBA. Optimal size - Oracle log_buffer sizing
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 …
Apr 16, 2001