remove event subscriptions from system topics

my powershell code is so slow to delete all the event subscriptins from the system topic.

# Get all event subscription names associated with the system topic
$subscriptions = az eventgrid system-topic event-subscription list --system-topic-name $systemTopicName --resource-group $resourceGroupName --query "[].name" -o tsv

# Iterate through each subscription and delete it
foreach ($sub in $subscriptions) {
    Write-Host "Deleting event subscription: $sub"
    az eventgrid system-topic event-subscription delete --system-topic-name $systemTopicName --resource-group $resourceGroupName --name $sub --yes
}

Is there any faster way to remove all the event subscriptions?

ForEach-Object -Parallel is available from Powershell v7.0 and can be used to parallelize work.

Try something like this (not tested):

# Get all event subscription names associated with the system topic
$subscriptions = az eventgrid system-topic event-subscription list --system-topic-name $systemTopicName --resource-group $resourceGroupName --query "[].name" -o tsv

# Iterate through each subscription and delete it
$subscriptions | Foreach-Object -Parallel {
    Write-Host "Deleting event subscription: $_"

    az eventgrid system-topic event-subscription delete --system-topic-name $systemTopicName --resource-group $resourceGroupName --name $_ --yes
} -ThrottleLimit 5

Please note that:

• The order of execution is not guaranteed
• The -ThrottleLimit parameter limits the number of script blocks running in parallel at a given time, and its default value is 5.

See ForEach-Object for more details and examples.