An adventure on SQL Server performance and features

Quickly move data between instances for testing using only PowerShell

Q

Quick tip, how many times did a dev ask you to move the PROD/QA data to DEV to test a feature? Of course, not the whole DB, which would be too easy via a scripted backup/restore, but only a single table, or subset of table data?

How do you deal with it usually? With the SSMS Import data Wizard? (ugh..) Exporting to flat file and reimporting? Linked Servers? External tools? Restore the whole database in the dev instance and extract the single table? Ignore the dev until it goes away?

The easiest way for me is using Powershell, like so:

### Parameters
$SourceInstance = 'SOURCEINSTANCE'
$SourceDB = 'SOURCEDB'
$SourceSchema = 'dbo'
$SourceTable = 'SOURCETABLE'

$DestinationInstance = 'DESTINATIONINSTANCE'
$DestinationDB = 'DESTINATIONDATABASE'
$DestinationSchema = 'dbo'
$DestinationTable = 'DESTINATIONTABLE'

### Parameters

$DataTable = Read-SqlTableData -TableName $SourceTable -SchemaName $SourceSchema -DatabaseName $SourceDB -ServerInstance $SourceInstance -Verbose

$DataTable | ConvertTo-DbaDataTable | Write-DbaDbTableData -Table $DestinationTable -Schema $DestinationSchema -Database $DestinationDB -SqlInstance $DestinationInstance -Truncate -KeepIdentity -AutoCreateTable -KeepNulls -BatchSize 50000

I’m using the sqlserver and dbatools Powershell modules to accomplish such a tedious task in the fastest way possibile.
The Write-DbaDbTableData cmdlet is pretty neat because it can create automatically the destination table if it doesn’t exists, truncate the table if it exists (or append, your choice), keep the identity values and nulls if necessary and everything is done via a bulk insert with a configurable batch size.

I’m pretty sure that the example above can be used to integrate a fully automated alignment process, give it a try!

Performance Note

I had to include ConvertTo-DbaDataTable in the Write-DbaDbTableData pipeline, because otherwise the cmdlet is not able to do a proper bulk insert, since as opposed to getting all the rows from the $DataTable and sending it in bulk to SQL Server, it fetches only one row at the time and does a lot of bulk inserts for single rows.
If you’re having performance issues with Write-DbaDbTableData keep this piece of information in mind.

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Emanuele Meazzo

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An adventure on SQL Server performance and features

Emanuele Meazzo

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