chart data oversize - get data from server

[alex]

Hello,
I have a pie chart that takes data from the backend in which a query to db is made.
the back end is written in python.
in the front end through angular I recover the response of the call and assign it to the pie datasource.
unfortunately the amount of data is very large and the graph is not constructed correctly.
how can I solve this problem?
can I put at least one default zoom to the chart?

this.myService.getPieChart(name, date1, date2).subscribe(data => {

    this.dataSourcePieChart= data;
},
(err) => {console.log("error");});

best regard,

alex