How to run Parallel Power Queries and Append them?

Hi, 
I am creating a report which uses Kusto Query Language which makes a Direct Query to Kusto Tables. Now, I am doing summarization tasks on Telemetry Data from the last 30 days and the visuals load very slowly because the computation takes too much time as the Data is humungous. So, I wanted to do parallel computation i.e. I split the Time Range into three different sets of 10 days each made 3 different queries and then appended the 1st and 2nd query into the third. But, I received an error message saying that this operation is not allowed in Direct Query. Can you tell me what other ways can be employed to perform a parallel compute? If not, how can I reduce my Query Execution time?

Thanks