4 In a Real Application Clusters (RAC) environment, the lock manager server (LMS) background process can post the log writer background process to write. When an exclusive current (XCUR) model buffer is transferred to another Oracle instance, the holding instance must complete the pending redo associated with the buffer, and the LMS is the process responsible for shipping the buffer to the other instance. During this transfer time, the LMS background process will post the wait event log file sync. Sometimes, the log writer background process will also flush consistent read (CR) buffers in an RAC envirionment. This activity can be monitered via the instance statistic views (for example, v$sysstat) statistic gc cr block flush time.

5 I feel very uncomfortable even writing about this! Don't ever say I didn't warn you about the potential loss of data.

6 I used OraPub's Statistical Significance Template spreadsheet. To locate and then download the spreadsheet for free, go to OraPub's web site and search for "stat sig."