commands

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Clear-DbaPlanCache

Author Tracy Boggiano, databasesuperhero.com
Availability Windows, Linux, macOS

 

Synopsis

Removes ad-hoc and prepared plan caches is single use plans are over defined threshold.

Description

Checks ad-hoc and prepared plan cache for each database, if over 100 MBs removes from the cache.

This command automates that process.

References: https://www.sqlskills.com/blogs/kimberly/plan-cache-adhoc-workloads-and-clearing-the-single-use-plan-cache-bloat/

Syntax

Clear-DbaPlanCache
    [[-SqlInstance] <DbaInstanceParameter[]>]
    [[-SqlCredential] <PSCredential>]
    [[-Threshold] <Int32>]
    [[-InputObject] <Object[]>]
    [-EnableException]
    [-WhatIf]
    [-Confirm]
    [<CommonParameters>]

 

Examples

 

Example: 1
PS C:\> Clear-DbaPlanCache -SqlInstance sql2017 -Threshold 200

Logs into the SQL Server instance "sql2017" and removes plan caches if over 200 MB.

Example: 2
PS C:\> Clear-DbaPlanCache -SqlInstance sql2017 -SqlCredential sqladmin

Logs into the SQL instance using the SQL Login 'sqladmin' and then Windows instance as 'ad\sqldba'
and removes if Threshold over 100 MB.

Example: 3
PS C:\> Find-DbaInstance -ComputerName localhost | Get-DbaPlanCache | Clear-DbaPlanCache -Threshold 200

Scans localhost for instances using the browser service, traverses all instances and gets the plan cache for each, clears them out if they are above 200 MB.

Optional Parameters

-SqlInstance

The target SQL Server instance or instances.

Alias
Required False
Pipeline false
Default Value
-SqlCredential

Login to the target instance using alternative credentials. Accepts PowerShell credentials (Get-Credential). Windows Authentication, SQL Server Authentication, Active Directory - Password, and Active Directory - Integrated are all supported. For MFA support, please use Connect-DbaInstance.

Alias
Required False
Pipeline false
Default Value
-Threshold

Memory used threshold.

Alias
Required False
Pipeline false
Default Value 100
-InputObject

Enables results to be piped in from Get-DbaPlanCache.

Alias
Required False
Pipeline true (ByValue)
Default Value
-EnableException

By default, when something goes wrong we try to catch it, interpret it and give you a friendly warning message. This avoids overwhelming you with "sea of red" exceptions, but is inconvenient because it basically disables advanced scripting. Using this switch turns this "nice by default" feature off and enables you to catch exceptions with your own try/catch.

Alias
Required False
Pipeline false
Default Value False
-WhatIf

If this switch is enabled, no actions are performed but informational messages will be displayed that explain what would happen if the command were to run.

Alias wi
Required False
Pipeline false
Default Value
-Confirm

If this switch is enabled, you will be prompted for confirmation before executing any operations that change state.

Alias cf
Required False
Pipeline false
Default Value

 

Want to see the source code for this command? Check out Clear-DbaPlanCache on GitHub.
Want to see the Bill Of Health for this command? Check out Clear-DbaPlanCache.