Comments on: SQL SERVER – Signal Wait Time Introduction with Simple Example – Wait Type – Day 2 of 28 http://blog.sqlauthority.com/2011/02/02/sql-server-signal-wait-time-introduction-with-simple-example-day-2-of-28/ Personal Notes of Pinal Dave Fri, 17 May 2013 15:26:57 +0000 hourly 1 http://wordpress.com/ By: SQL SERVER – Weekly Series – Memory Lane – #015 « SQL Server Journey with SQL Authority http://blog.sqlauthority.com/2011/02/02/sql-server-signal-wait-time-introduction-with-simple-example-day-2-of-28/#comment-419689 Sat, 09 Feb 2013 01:31:03 +0000 http://blog.sqlauthority.com/?p=11454#comment-419689 [...] Signal Wait Time Introduction with Simple Example – Wait Type – Day 2 of 28 [...]

]]> By: Krp http://blog.sqlauthority.com/2011/02/02/sql-server-signal-wait-time-introduction-with-simple-example-day-2-of-28/#comment-382519 Wed, 28 Nov 2012 11:49:11 +0000 http://blog.sqlauthority.com/?p=11454#comment-382519 Nice write Pinal, thanks.
Now my wait_type is Async_Network_Io and it is in suspended state. Any idea what shuld be the quick resolution? even after clearing the proc cache? Thanks

]]> By: Tom http://blog.sqlauthority.com/2011/02/02/sql-server-signal-wait-time-introduction-with-simple-example-day-2-of-28/#comment-302861 Mon, 18 Jun 2012 15:47:41 +0000 http://blog.sqlauthority.com/?p=11454#comment-302861 Hi Pinal!

I just started using your query recently to monitor CPU pressure. After seeing what looked like spikes in signal wait time, I added some more detail to your query to show the magnitude of the percentages shown in the query. After seeing this data, I realized that what appeared to be spikes in signal wait time could be ignored.

Note, I have been collecting wait stats data hourly on all SQL Servers and then reporting the CPU pressure once per day for successive samples over the last 24 hours.

SUM(s2.signal_wait_time_ms – s1.signal_wait_time_ms) as signal_wait_time_ms_diff
, SUM((s2.wait_time_ms – s1.wait_time_ms) – (s2.signal_wait_time_ms – s1.signal_wait_time_ms)) as resource_wait_time_ms_diff

]]> By: StingRayy http://blog.sqlauthority.com/2011/02/02/sql-server-signal-wait-time-introduction-with-simple-example-day-2-of-28/#comment-270768 Mon, 02 Apr 2012 09:15:06 +0000 http://blog.sqlauthority.com/?p=11454#comment-270768 Hi,

Im an sql amateur and was just wondering where do i find or how do i create this sys.dm_os_wait_stats table, cause if i run this, it tells me procedure does not exist.

Thank u in advance

]]> By: Ali http://blog.sqlauthority.com/2011/02/02/sql-server-signal-wait-time-introduction-with-simple-example-day-2-of-28/#comment-168800 Fri, 16 Sep 2011 18:19:15 +0000 http://blog.sqlauthority.com/?p=11454#comment-168800 Amazing Analogy.

]]> By: Ananda http://blog.sqlauthority.com/2011/02/02/sql-server-signal-wait-time-introduction-with-simple-example-day-2-of-28/#comment-121185 Mon, 28 Feb 2011 12:37:19 +0000 http://blog.sqlauthority.com/?p=11454#comment-121185 Hi friends

Mr. Pinal Dave wait stats articles very useful for me, it really great.

I executed on of my production server it looks like somewhat good in CPU waits stats, and resource waits is very high.

Please tell me how to reduce resource wait time on server.

%signal (cpu) waits – 22.25
%resource waits – 77.75

Thanks
ananda

]]> By: Rama http://blog.sqlauthority.com/2011/02/02/sql-server-signal-wait-time-introduction-with-simple-example-day-2-of-28/#comment-116176 Sat, 05 Feb 2011 12:24:04 +0000 http://blog.sqlauthority.com/?p=11454#comment-116176 Hi Pinal,

Excelent analogy. Thanks for expaining this complex topic.

Rama

]]> By: Claire http://blog.sqlauthority.com/2011/02/02/sql-server-signal-wait-time-introduction-with-simple-example-day-2-of-28/#comment-115688 Wed, 02 Feb 2011 17:43:06 +0000 http://blog.sqlauthority.com/?p=11454#comment-115688 Hi Pinal,
Excellent analogy! Though if it were me, I might have waited for a cab that did accept credit cards :) Makes sense that lower single wait stats would be better for the system.

]]> By: Feodor Georgiev http://blog.sqlauthority.com/2011/02/02/sql-server-signal-wait-time-introduction-with-simple-example-day-2-of-28/#comment-115642 Wed, 02 Feb 2011 09:09:22 +0000 http://blog.sqlauthority.com/?p=11454#comment-115642 Great article, Pinal!

Think about it this way: a database system is much more complex than the SQL Server by itself. The reason being is that there are other components involved in “the big picture”.
Wat I am trying to say is that the internal waits, which are the topic of this article, are just a small part of the game, since the database system depends on the client system, networking, error handling, and so on. In other words, if you have a client application which sends adhoc queries of 80kb each 100 times per minute (trust me, I have seen this), then you will depend on the network, NIC configuration, internal SQL parsing, processing, plan generation, query execution, and if the dataset returned is large, then you will also depend on the NIC and the network.
Unfortunately, SQL Server is not too aware of other wait stats, aside from its own internal ones. (well, there are some network async IO stats, but it does not say who know how much about the cause of the problem)

The bottom line: when we talk about waits, keep in mind the “big picture”.

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