Microsoft® SQL Server® 2012 Bible

939

Chapter 40: Extended Events

40

Events

An Event is an interesting point in the SQL Server executable code. Events in Extended

Events are similar in concept to SQL Trace events in that they represent specifi c data points

that you want to capture. Everything in Extended Events centers on the Event object

because it is the fulcrum on which all other Extended Events objects rely. Each Event has

a default set of fi elds associated with the payload information the event delivers. Other

information can be gathered for the Event through Actions.

Use the following query to fi nd all available Extended Events and the Package they belong

to:

SELECT

PackageName = p.name, EventName = o.name,

EventDescription = o.description

FROM sys.dm_xe_objects o

JOIN sys.dm_xe_packages p ON o.package_guid = p.guid

WHERE object_type = 'event'

Actions

An Action is the response to a captured Event. In most cases in Extended Events, you use

Actions to acquire additional data not present in the default payload of the Event you cap-

ture. However, they can be used for other reasons, such as triggering a stack dump. Actions

always occur synchronously, so capturing too many Actions may hinder the performance of

Extended Events.

Use the following query to fi nd all available Extended Events Actions and the Package they

belong to:

SELECT

PackageName = p.name, ActionName = o.name,

ActionDescription = o.description

FROM sys.dm_xe_objects o

JOIN sys.dm_xe_packages p ON o.package_guid = p.guid

WHERE object_type = 'action'

Targets

A Target is the consumer of captured Extended Events data. The two formats for Targets are

either a fi le destination or an in-memory destination, of which there are several formats. Targets

can consume data synchronously or asynchronously depending on the type of the Target.

Use the following query to fi nd all available Extended Events Targets and the Package they

belong to:

SELECT

PackageName = p.name, TargetName = o.name,

TargetDescription = o.description

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