Hi All,
I am a database administrator. I am recently noted the database performance statistic is bad, the average of PLE (Page Life Expectancy) is at 100 seconds. From the opinion of DBA and my experience , this is at critical status. Slowness and connection timeout might happen frequently.
However we don't receive any complain from user, but I checked the most of wait_type(refer to below Top 10 wait_type in our environment) in SQL server is PAGEIOLATCH. Is anybody has experience about it? How about the PLE in your SAP databases?
wait_type waiting_tasks_count wait_time_ms max_wait_time_ms signal_wait_time_ms
PAGEIOLATCH_SH 1156589452 2659974311 63800 15378169
BACKUPIO 19610826 657041858 4670360 262921
BACKUPBUFFER 25824541 648582462 2970 556802
ASYNC_IO_COMPLETION 577 638762337 48232539 52
ASYNC_NETWORK_IO 190891365 251906374 20017 14915510
OLEDB 3647296854 119428335 558205 0
SOS_SCHEDULER_YIELD 665857762 117258566 127194 116444918
PAGEIOLATCH_EX 39470662 97370920 22808 598543
WRITELOG 29602224 96961716 7191 3102182
MSQL_XP 191835 15575437 190774 0
You can get the PLE from the SQL server by below command:
SELECT getdate() [current_time],[counter_name],[cntr_value]
FROM sys.dm_os_performance_counters
WHERE [object_name] LIKE '%Manager%'
AND [counter_name] = 'Page life expectancy'
end