functions/Clear-DbaPlanCache.ps1
|
function Clear-DbaPlanCache { <# .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/ .PARAMETER SqlInstance The target SQL Server instance or instances. .PARAMETER 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. .PARAMETER Threshold Memory used threshold. .PARAMETER InputObject Enables results to be piped in from Get-DbaPlanCache. .PARAMETER 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. .PARAMETER Confirm If this switch is enabled, you will be prompted for confirmation before executing any operations that change state. .PARAMETER 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. .NOTES Tags: Memory Author: Tracy Boggiano, databasesuperhero.com Website: https://dbatools.io Copyright: (c) 2018 by dbatools, licensed under MIT License: MIT https://opensource.org/licenses/MIT .LINK https://dbatools.io/Clear-DbaPlanCache .EXAMPLE PS C:\> Clear-DbaPlanCache -SqlInstance sql2017 -Threshold 200 Logs into the SQL Server instance "sql2017" and removes plan caches if over 200 MB. .EXAMPLE 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 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. #> [CmdletBinding(SupportsShouldProcess)] param ( [DbaInstanceParameter[]]$SqlInstance, [PSCredential]$SqlCredential, [int]$Threshold = 100, [parameter(ValueFromPipeline)] [object[]]$InputObject, [switch]$EnableException ) process { foreach ($instance in $SqlInstance) { $InputObject += Get-DbaPlanCache -SqlInstance $instance -SqlCredential $SqlCredential } foreach ($result in $InputObject) { if ($result.MB -ge $Threshold) { if ($Pscmdlet.ShouldProcess($($result.SqlInstance), "Cleared SQL Plans plan cache")) { try { $server = Connect-SqlInstance -SqlInstance $result.SqlInstance -SqlCredential $SqlCredential } catch { Stop-Function -Message "Error occurred while establishing connection to $instance" -Category ConnectionError -ErrorRecord $_ -Target $instance -Continue } $server.Query("DBCC FREESYSTEMCACHE('SQL Plans')") [PSCustomObject]@{ ComputerName = $result.ComputerName InstanceName = $result.InstanceName SqlInstance = $result.SqlInstance Size = $result.Size Status = "Plan cache cleared" } } } else { if ($Pscmdlet.ShouldProcess($($result.SqlInstance), "Results $($result.Size) below threshold")) { [PSCustomObject]@{ ComputerName = $result.ComputerName InstanceName = $result.InstanceName SqlInstance = $result.SqlInstance Size = $result.Size Status = "Plan cache size below threshold ($Threshold) " } Write-Message -Level Verbose -Message "Plan cache size below threshold ($Threshold) " } } } } } |