Oracle Database 11 g - Online Public Access Catalog

CHAPTER 10 ■ DATA GUARD 431from the logwriter network server (LNS) process before terminating the connection. This parameterby default is set to 30 seconds.■Note Oracle recommends that you set the net_timeout parameter for the Maximum Protection andMaximum Availability databases.The net_timeout parameter populates a histogram of response time values for theV$REDO_DEST_RESP_HISTOGRAM dynamic view. There is one entry for every synchronousredo transport destination. The maximum allowable value for the net_timeout parameteris 1,200 seconds.You can query V$REDO_DEST_RESP_HISTOGRAM to determine the response time foreach transport destination. The DEST_ID column correlates to the log_archive_dest_n parameter.The DURATION column can have the following values:• 1–300 (shows actual seconds rounded up)• 600 (301–600 seconds show the value of 600)• 1,200 (601–1,200 seconds show the value of 1,200)• 2,400 (1,201–2,400 seconds show the value of 2,400)• 4,800 (2,401–4,800 seconds show the value of 4,800)• 9,600 (anything greater than 4,801 seconds shows the value of 9,600)For ease of management, the numbers in this column are reported in seconds only for thefirst 300 seconds. For all values less than 300 seconds, the DURATION column reports the timerounded to the nearest second. For values larger than 300 seconds, Oracle rounds up to thenext increment of 600, 1,200, 2,400, 4,800, or 9,600 seconds.This is the makeup of the histogram view:SQL> desc V$REDO_DEST_RESP_HISTOGRAMName Null? Type------------------------ -------- ---------------DEST_IDNUMBERTIMEVARCHAR2(20)DURATIONNUMBERFREQUENCYNUMBERYou should carefully observe the FREQUENCY column to review the bucket counts to determinean appropriate value for net_timeout. A high bucket count suggests a good value for thenet_timeout attribute.Here’s a sample query to display a response time histogram for the second archivedestination: