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Home -> Community -> Mailing Lists -> Oracle-L -> RE: sysstat table..
Taken straight from the 8i Reference manual:
redo wastage
Number of bytes wasted because redo blocks needed to be written before they are completely full. Early writing may be needed to commit transactions, to be able to write a database buffer, or to switch logs.
redo writer latching time
Elapsed time in 10s of milliseconds needed by LWGR to obtain and release each copy latch.
redo log space wait time
Total elapsed waiting time for "redo log space requests" in 10s of milliseconds.
redo log space requests
Number of times the active log file is full and Oracle must wait for disk space to be allocated for the redo log entries. Such space is created by performing a log switch. Log files that are small in relation to the size of the SGA or the commit rate of the work load can cause problems. When the log switch occurs, Oracle must ensure that all committed dirty buffers are written to disk before switching to a new log file. If you have a large SGA full of dirty buffers and small redo log files, a log switch must wait for DBWR to write dirty buffers to disk before continuing.
Also examine the log file space and log file space switch wait events in V$SESSION_WAIT.
HTH, and manuals do actually hold some information believe it or not :)
Mark
-----Original Message-----
Sent: Monday, July 02, 2001 09:20
To: Multiple recipients of list ORACLE-L
hi all,
can anybody explain me what does the following statistics means from my sysstat table.
redo entries 10476 redo size 2851660 redo buffer allocation retries 5 redo wastage 1044924 redo writer latching time 73 redo writes 3465 redo blocks written 7851 redo write time 6583 redo log space requests 16 redo log space wait time 1438 redo log switch interrupts 0 redo ordering marks 0
Saurabh Sharma
saurabh.sh_at_usa.net
http://www.geocities.com/saurabh00pc/stride.html
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Author: Mark Leith
INET: mark_at_cool-tools.co.uk
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