Angular Odata what is the best way to batch queries

Question

I'm currently trying to synchronize huge data from ODATA 4 webservice into an ionic SQLite database.

The entity I'm trying to fetch contains like 100k rows.

What is the best way to batch it ?

Actually, I'm doing the following steps :

 private top: number = 800;
 private skip: number = 0;
  
  synchronize() {
    let service = this.factory.entitySet<Entity>("Entity");
    let serviceEntities = ireService.entities();

    return serviceEntities
      .query((q) => {
        q.top(this.top);
        q.skip(this.skip);
      })
      .fetch()
      .subscribe(({ entities }) => {
        if (entities!.length === this.top) {
          this.skip += this.top;
          this.synchronize();
        }
      });
  }

It's working fine but when I call synchronize() I would like to be able to wait the end of the excution of the whole batch but I don't really know how do it. Should I return something ?