Comments on: Level 1: Overview http://ashmasters.com The ASH Masters Demoground Wed, 27 Apr 2011 22:27:24 +0000 hourly 1 http://wordpress.org/?v=3.2 By: pioro http://ashmasters.com/ash-queries/overview-queries/comment-page-1/#comment-3491 pioro Tue, 20 Oct 2009 13:19:40 +0000 http://ashmasters.oracloid.com/?page_id=4#comment-3491 Hi Kyle, I'm wondering if you still maintain that blog but I have a question about aveact.sql file linked above. In your script you are calculating waits using following formula (for both - online and historical) sum(decode(session_type,'BACKGROUND',0,decode(session_state,'WAITING',10,0))) waits but in results (linked above too) you have a strange values in wait column @aveact TM NPTS AVEACT GRAPH CPU WAITS ---------------- ------ ------- ---------------------- ---- ----- 06-AUG 13:00:00 270 .33 - 2 29 59 06-AUG 14:00:00 1040 2.24 --------2--- 341 1984 06-AUG 15:00:00 623 6.67 ------2---------- 438 3718 06-AUG 16:00:00 1088 2.59 --------2---- 335 2486 How is it possible that sum is 59 when we use 10s as a basic value ? I assume it should be 1 for both - CPU and wait - and there is a bug inside that script. I'm wondering why you using 1's for ash and 10's for historical ash ? This is very useful tool - Thanks for that regards, Marcin Hi Kyle,

I’m wondering if you still maintain that blog but I have a question about aveact.sql file linked above. In your script you are calculating waits using following formula (for both – online and historical)

sum(decode(session_type,’BACKGROUND’,0,decode(session_state,’WAITING’,10,0))) waits

but in results (linked above too) you have a strange values in wait column

@aveact
TM NPTS AVEACT GRAPH CPU WAITS
—————- —— ——- ———————- —- —–
06-AUG 13:00:00 270 .33 – 2 29 59
06-AUG 14:00:00 1040 2.24 ——–2— 341 1984
06-AUG 15:00:00 623 6.67 ——2———- 438 3718
06-AUG 16:00:00 1088 2.59 ——–2—- 335 2486

How is it possible that sum is 59 when we use 10s as a basic value ?
I assume it should be 1 for both – CPU and wait – and there is a bug inside that script.

I’m wondering why you using 1′s for ash and 10′s for historical ash ?

This is very useful tool – Thanks for that

regards,
Marcin

]]> By: Doug's Oracle Blog http://ashmasters.com/ash-queries/overview-queries/comment-page-1/#comment-385 Doug's Oracle Blog Wed, 10 Dec 2008 05:01:37 +0000 http://ashmasters.oracloid.com/?page_id=4#comment-385 [...] the timings in the individual session samples rather than COUNTing them as a proxy for time. (See here for a brief discussion about that, but it probably merits a future post here too.) He showed more [...] [...] the timings in the individual session samples rather than COUNTing them as a proxy for time. (See here for a brief discussion about that, but it probably merits a future post here too.) He showed more [...]

]]> By: khailey http://ashmasters.com/ash-queries/overview-queries/comment-page-1/#comment-79 khailey Mon, 14 Jul 2008 18:52:38 +0000 http://ashmasters.oracloid.com/?page_id=4#comment-79 Anthony, I think your question is "why am I graphing an events and cpu instead of wait time?" wait_time is just a proxy for whether we are waiting or on CPU. THe time_waited actually doesn't tell us much about system load in ASH data since ASH is sampled we generally get long waits and miss short waits so the data is skewed. On the other hand the sampling of the number of active sessions is a great statistical approximation of load on the system and looking at how much o fhte load is waiting verses working (on CPU) gives us even more information. Anthony, I think your question is “why am I graphing an events and cpu instead of wait time?” wait_time is just a proxy for whether we are waiting or on CPU. THe time_waited actually doesn’t tell us much about system load in ASH data since ASH is sampled we generally get long waits and miss short waits so the data is skewed. On the other hand the sampling of the number of active sessions is a great statistical approximation of load on the system and looking at how much o fhte load is waiting verses working (on CPU) gives us even more information.

]]> By: Anthony http://ashmasters.com/ash-queries/overview-queries/comment-page-1/#comment-78 Anthony Mon, 14 Jul 2008 18:05:20 +0000 http://ashmasters.oracloid.com/?page_id=4#comment-78 Just curious as to why you are counting occurrences of events/CPU instead of using wait_time/time_waited values in ASH. Just curious as to why you are counting occurrences of events/CPU instead of using wait_time/time_waited values in ASH.

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