Search Results for “index fragmentation”

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1.1 Indexes: How to Think Like the Engine (110m)

When you pass in a query, how does SQL Server build the results? We’ll role play: Brent Ozar will be an end user sending in queries, and you’ll be the SQL Server engine. Using simple spreadsheets as your tables, you’ll learn how SQL Server builds execution plans, uses indexes, performs joins, and considers statistics. This…

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Rebuilding Indexes Can Slow Queries Down

Index Maintenance
6 Comments
Today, Jonathan Kehayias wrote about how fragmentation impacts execution plans. I’m really into performance tuning, so I read the post carefully, really interested to see how it impacted query runtime. You should read it too – it’s a great post with a solid demo. But oddly, he didn’t mention the query speeds. I thought that was…
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Index Maintenance Madness

SQL Server
36 Comments
When we look at a new server, we check out their database maintenance jobs, making sure their server is in a safe place before we dig into their pain points. We verify if their backups and DBCC CHECKDB jobs can meet their RPO/RTO goals. We also check out their index maintenance jobs, if any. When…
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Mastering Index Tuning

Mastering Index Tuning

41 customer reviews

You need to speed up a SQL Server app, but you only want to make index changes. You don’t want to buy hardware, change SQL Server, or change the code. Good news – I’ll teach you how in 3 days of learning and fun.

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3.6 Index Maintenance for Enterprise Environments (43m)

10 Comments
You’ve learned over time that maintenance plans are the wrong way to go, and you’ve implemented index maintenance scripts from Ola Hallengren, the MidnightDBAs, or Michelle Ufford. However, you’re not really sure exactly what you’re fixing, or if it’s the least invasive way to improve performance. Learn the difference between internal and external fragmentation, see…
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Indexes For Kids

Indexing, SQL Server
18 Comments
Kid Tested When you work with something a lot, you tend to extrapolate concepts from it out to everything you see. That one person collecting tickets is a serial zone. That food truck line is a HEAP. The empty subway car that smells like a toilet is Replication. Stuff like that. If you have one…
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Testing ALTER INDEX REBUILD with WAIT_AT_LOW_PRIORITY in SQL Server 2014

One of the blocking scenarios I find most interesting is related to online index rebuilds. Index rebuilds are only mostly online. In order to complete they need a very high level of lock: a schema modification lock (SCH-M). Here’s one way this can become a big problem: An online index rebuild starts against a large index A…
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