Partial query failure: Low memory condition Kusto

such errors can be a result of a non-optimized workload running against your cluster.
the recommendation is to make sure your queries are following query best practices: https://docs.microsoft.com/en-us/azure/kusto/query/best-practices.
This specific error is not necessarily coming from your own query (though it might) – it means that at least on one machines in the cluster the free memory is running low.
If this issue persists and optimizing the query according to the guidelines above doesn't not help in alleviating it, you should open consider opening a support ticket for your resource