August 2012
Intermediate to advanced
1416 pages
33h 39m
English
book
Microsoft SQL Server 2012 Bible
by Adam Jorgensen, Jorge Segarra, Patrick LeBlanc, Jose Chinchilla, Aaron Nelson
Content preview from Microsoft SQL Server 2012 Bible
Become an O’Reilly member and get unlimited access to this title plus top books and audiobooks from O’Reilly and nearly 200 top publishers, thousands of courses curated by job role, 150+ live events each month,
O’Reilly covers everything we've got, with content to help us build a world-class technology community, upgrade the capabilities and competencies of our teams, and improve overall team performance as well as their engagement.I wanted to learn C and C++, but it didn't click for me until I picked up an O'Reilly book. When I went on the O’Reilly platform, I was astonished to find all the books there, plus live events and sandboxes so you could play around with the technology.I’ve been on the O’Reilly platform for more than eight years. I use a couple of learning platforms, but I'm on O'Reilly more than anybody else. When you're there, you start learning. I'm never disappointed.I'm always learning. So when I got on to O'Reilly, I was like a kid in a candy store. There are playlists. There are answers. There's on-demand training. It's worth its weight in gold, in terms of what it allows me to do.
Examining Wait Statistics
You can retrieve wait statistic information in many ways. In this chapter, you examine three different dynamic management views (DMV) to use to gather this information.
Executing Requests
To view all tasks currently executing, use the DMV sys.dm_exec_requests (see Figure 39.1). This DMV includes information for all tasks that are currently executing (running), currently waiting on a resource (suspended), or currently waiting their turn to get on the scheduler to execute (runnable). Use this DMV for a high-level overview of all tasks currently executing on your SQL Server Instance.
Figure 39.1 Querying sys.dm_exec_requests for any request that has a status of running, suspended, or runnable. The query returns the current wait type of the request as well as the last wait type, and the total elapsed time for the request.
Wait Stats
The DMV sys.dm_os_wait_stats (see Figure 39.2) returns the aggregated time waited, by wait type, since the last time SQL Server was restated or the last time the DMV was cleared. Use this DMV to see a holistic view of all the wait times on your system to see where SQL Server spends its time waiting. Many waits returned in this DMV are benign waits and should be ignored, even if they are high on the waiting list. Later in this chapter you review some common waits to watch if they represent a high percentage of wait time on your ...
Become an O’Reilly member and get unlimited access to this title plus top books and audiobooks from O’Reilly and nearly 200 top publishers, thousands of courses curated by job role, 150+ live events each month,
and much more.
Read now
Unlock full access
More than 5,000 organizations count on O’Reilly
O’Reilly covers everything we've got, with content to help us build a world-class technology community, upgrade the capabilities and competencies of our teams, and improve overall team performance as well as their engagement.Julian F.
I wanted to learn C and C++, but it didn't click for me until I picked up an O'Reilly book. When I went on the O’Reilly platform, I was astonished to find all the books there, plus live events and sandboxes so you could play around with the technology.Addison B.
I’ve been on the O’Reilly platform for more than eight years. I use a couple of learning platforms, but I'm on O'Reilly more than anybody else. When you're there, you start learning. I'm never disappointed.Amir M.
I'm always learning. So when I got on to O'Reilly, I was like a kid in a candy store. There are playlists. There are answers. There's on-demand training. It's worth its weight in gold, in terms of what it allows me to do.