functions/Read-DbaTransactionLog.ps1
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function Read-DbaTransactionLog { <# .SYNOPSIS Reads the live Transaction log from specified SQL Server Database .DESCRIPTION Using the fn_dblog function, the live transaction log is read and returned as a PowerShell object This function returns the whole of the log. The information is presented in the format that the logging subsystem uses. A soft limit of 0.5GB of log as been implemented. This is based on testing. This limit can be overridden at the users request, but please be aware that this may have an impact on your target databases and on the system running this function .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 Database Database to read the transaction log of .PARAMETER IgnoreLimit Switch to indicate that you wish to bypass the recommended limits of the function .PARAMETER RowLimit Will limit the number of rows returned from the transaction log .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: Database, Log, LogFile Author: Stuart Moore (@napalmgram), stuart-moore.com Website: https://dbatools.io Copyright: (c) 2018 by dbatools, licensed under MIT License: MIT https://opensource.org/licenses/MIT .EXAMPLE PS C:\> $Log = Read-DbaTransactionLog -SqlInstance sql2016 -Database MyDatabase Will read the contents of the transaction log of MyDatabase on SQL Server Instance sql2016 into the local PowerShell object $Log .EXAMPLE PS C:\> $Log = Read-DbaTransactionLog -SqlInstance sql2016 -Database MyDatabase -IgnoreLimit Will read the contents of the transaction log of MyDatabase on SQL Server Instance sql2016 into the local PowerShell object $Log, ignoring the recommendation of not returning more that 0.5GB of log #> [CmdletBinding(DefaultParameterSetName = "Default")] param ( [parameter(Mandatory)] [DbaInstanceParameter]$SqlInstance, [PSCredential]$SqlCredential, [parameter(Mandatory)] [object]$Database, [Switch]$IgnoreLimit, [int]$RowLimit = 0, [switch]$EnableException ) try { $server = Connect-SqlInstance -SqlInstance $SqlInstance -SqlCredential $SqlCredential } catch { Stop-Function -Message "Error occurred while establishing connection to $SqlInstance" -Category ConnectionError -ErrorRecord $_ -Target $instance -Continue return } if (-not $server.databases[$Database]) { Stop-Function -Message "$Database does not exist" return } if ('Normal' -notin ($server.databases[$Database].Status -split ',')) { Stop-Function -Message "$Database is not in a normal State, command will not run." return } if ($RowLimit -gt 0) { Write-Message -Message "Limiting results to $RowLimit rows" -Level Verbose $RowLimitSql = " TOP $RowLimit " $IgnoreLimit = $true } else { $RowLimitSql = "" } if ($IgnoreLimit) { Write-Message -Level Verbose -Message "Please be aware that ignoring the recommended limits may impact on the performance of the SQL Server database and the calling system" } else { #Warn if more than 0.5GB of live log. Dodgy conversion as SMO returns the value in an unhelpful format :( $SqlSizeCheck = "select sum(FileProperty(sf.name,'spaceused')*8/1024) as 'SizeMb' from sys.sysfiles sf where CONVERT(INT,sf.status & 0x40) / 64=1" $TransLogSize = $server.Query($SqlSizeCheck, $Database) if ($TransLogSize.SizeMb -ge 500) { Stop-Function -Message "$Database has more than 0.5 Gb of live log data, returning this may have an impact on the database and the calling system. If you wish to proceed please rerun with the -IgnoreLimit switch" return } } $sql = "select $RowLimitSql * from fn_dblog(NULL,NULL)" Write-Message -Level Debug -Message $sql Write-Message -Level Verbose -Message "Starting Log retrieval" $server.Query($sql, $Database) } |