Bushmelev Anton save at my blog, original Waits on the cache buffer chains latch, ie the wait event «latch: cache buffers chains» happen when there is extremely high and concurrent access to the same block in a database. Access to a block is normally a fast operation but if concurrent users access a block fast enough, repeatedly … Читать далее
perf-tools looks awesome example :
now catalog works fine:
[oracle@p00xxxdb01 ~]$ srvctl status database -d p00xxx PRCD-1027 : Failed to retrieve database p00xxx PRCD-1229 : An attempt to access configuration of database p00xxx was rejected because its version 11.2.0.2.0 differs from the program version 11.2.0.4.0. Instead run the program from /oracle/app/base/db/11.2.0.2. [oracle@p00xxxdb01 ~]$ srvctl upgrade database -d p00xxx -o /oracle/app/base/db/11.2.0.4 [oracle@p00xxxdb01 ~]$
awr_top2 script ASH_SQLMON look at plan line 3 in ash: this substr(this_.response_content, 0, 5) query high compressed clob field after talking with the developers on the subject, why would they need these first 5 characters, they agreed to remove them from the query. After editing query the server load is 3 times lower
cool =) does not know that it can be done such way alter system set events ‘ xxx trace name context level 12, lifetime 1’; more at : blog.tanelpoder.com
On Linux, Automatic Storage Management uses asynchronous Input-Output by default. if database files are not on asm: save a lot of time later, need for logminer: setup awr snapshot retention: in case with ADG: Installing and Using Standby Statspack in 11g (Doc ID 454848.1)