Basically, I have a query from Firestore, and some of the filter fields may be empty, in that case the specific query will be ignored,Since inequality queries with multiple fields requires indexes, what's the best way to create indexes of such query without going through all possible combinations.

e.g, 'country' and 'budget_high', 'gender' and 'budget_high', 'age' and 'budget_high', 'country, gender' and 'budget_high' and so on.

This is my query.

if (country !== "") query = query.where("country", "==", country);
  if (gender !== "") query = query.where("gender", "==", gender);
  if (age !== "") query = query.where("age", "==", age);
  if (religion !== "") query = query.where("religion", "==", religion);
  if (budget_high !== "") query = query.where("budget_high", "<=", Number(budget_high));
  return query
    .get()
    .then((querySnapshot) => {
      var data = [];
      querySnapshot.forEach((doc) => {
        let user_data = doc.data();
        user_data.created_at = `${user_data.created_at.toDate()}`;
        data.push(user_data);
      });
      return data;
    })
    .catch((error) => {
      console.log("Error getting documents: ", error);
      return [];
    });
};

Here are my Single Field Exemptions for collection (not collection group)