The Art ofIndexing

Ken Simmons

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Who is this guy?

DBADeveloperAuthorSQL Server MVPIT Industry for 10+ years

ObjectivesIntroduce the different kinds of indexes and index options along with best practices for using them.Provide strategies for creating indexes by taking advantage of DMVs and the Plan Cache.Cover the various ways indexes can degrade performance along with options for finding and removing them.

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The Boring Technical

Stuffhttp://www.flickr.com/photos/paraflyer/386529128/

Types of Indexes

ClusteredNon ClusteredUniqueFilteredFull-TextSpatialXML

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Types of Indexes

ClusteredNon ClusteredUniqueFilteredFull-TextSpatialXML

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Types of Indexes

ClusteredNon ClusteredUniqueFilteredFull-TextSpatialXML

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Types of Indexes

ClusteredNon ClusteredUniqueFilteredFull-TextSpatialXML

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Regulations1 Clustered Index249 Non Clustered (2005)999 Non Clustered (2008)16 Columns or 900 Bytes

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CharacteristicsClustered IndexNarrowUniqueStaticIncreasing

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CharacteristicsClustered IndexNarrow

Less Data DuplicatedSmaller…

DatabasesBackupsMaintenance times

UniqueStaticIncreasing

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CharacteristicsClustered IndexNarrowUnique

Not Required4 Byte UniquifierNarrow Remember?

StaticIncreasing

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CharacteristicsClustered IndexNarrowUniqueStatic

Changes Cause… Additional Overhead for Non Clustered Indexes

Clustered Index Fragmentation

Increasinghttp://www.flickr.com/photos/st3f4n/4085958000/

CharacteristicsClustered IndexNarrowUniqueStaticIncreasing

Data is added to the end of the Index

Reduces Page Splits and Fragmentation

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CharacteristicsNon Clustered IndexCover Common QueriesLink to Clustered Index

Lookup

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The Cool Stuff

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Demo

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SELECT http://www.flickr.com/photos/funky64/3485138671/

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What about the thousands of other queries that run on my server?

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PerspectiveBetter

DMVs Provide a

Index UsageUnused IndexesExpensive To Maintain

Missing IndexesNo Query Information

Plan CacheQueryExecution PlanMissing Index Informationhttp://www.flickr.com/photos/danorbit/346563918/

Demo

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IntelligentMakeDecision

s

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Demo

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Review•Clustered Indexes•Unique, Narrow, Static, Increasing

•Non-Clustered Indexes•Cover Queries Not Covered By The Clustered Index•Use INCLUDE To Cover Non-Key Columns

•Use DMVs To Get A Better Perspective•Unused Indexes, Missing Indexes, Cached Plans

•Make Intelligent Decisions When Applying Indexes•Don’t Apply Indexes Based On Recommendations

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Contact InfoBlog

http://cybersql.blogspot.com/Email

kensimmonsii@gmail.comTwitter @KenSimmons

http://twitter.com/KenSimmonsLinkedIN

http://www.linkedin.com/in/kensimmons