Inside disappeared nikon cf card recovery software , in the event you encounter this kind of situation, then give priority to set '_use_adaptive_log_file_sync' = false, adaptivelogfilesync is often a new feature proposed in 11.two to optimize redo log writing, defaults to True following 11.two.0.3.
You'll find circumstances exactly where the typical wait time of logfilesync wait events has dropped from 10ms to 1 ~ 2ms after '_use_adaptive_log_file_sync' = false.
The cause of _use_adaptive_log_file_sync's performance degradation may very well be that it causes LGWR to utilize polling instead of post / wait, as well as the polling interval is 10ms, which is written dead within the code.
Furthermore, should you use Veritas / symantec's ODM, you also need to pay unique focus: you could encounter Bug13551402High 'logfileparallelwrite' and 'logfilesync' afterupgrading 11.2withVeritas / SymantecODM, this BUG has been confirmed to exist on 11.two.0.three and 11.two.0.2.
The internal discussion of the bug finally confirmed that for the reason that lgwr's IO in 11.2 utilised a batch synchronous I / O interface, it brought on performance degradation when made use of with Veritas / symantec's ODM.
At disappeared lexar cf card recovery software , the bug has been patched on a number of Unix / Linux platforms:
Related articles | Relatedposts:
ScripttoCollectLogFileSyncDiagnosticInformation (lfsdiag.sql) Scriptsetechooffsetfeedbackoffcolumntimecolnew ...
dbfileparallelwrite wait for the event ThiseventoccursintheDBWR.Itindicatesthatthe ...
In-depth understanding of the dbfileparallelread wait event The userI / O form of physical read wait events that we commonly see on weekdays incorporate dbfilesequentialread and dbfi […] ...
dbfileparallelread waiting for the occasion TheprocesshasissuedmultipleI / Orequestsinparalle […] ...
Oracle wait event: Datafileinitwrite waits for any datafileinitwrite wait occasion when adding a clob column with a default value to a big table. This waits […] ...
The weblog posts of gcbufferbusy / gcslogflushsync and logfilesync collate my personal posts: gccurrentblockbusy and redologflush in RAC […] ...
[Oracle Performance Optimization] Maclean Tuning Course Outline SQL Optimization Course: Understanding OracleDB Architecture SQL Optimization Introduction Optimization Procedures Easy ...
fileopen wait occasion Thiswaiteventisexperiencedwheneverthedatabasene […] ...
VeritasODMAsyncandOracle just says that filesystemio_options isn't effective for VeritasVxfs and ODMFILE (Th […] ...
Why does logfilesync (in fact slow to create redo) lead to bufferbusywait? Within the write-up 'gcbufferbusy / gcslogflushsync and logfilesync', I introduced […] ...
Comments