[英]How does Objectify query works
Suppose I have this code: 假设我有以下代码:
Query<Car> q = ofy().load().type(Car.class);
for (Car car : q) {
// Do something with car...
}
How does Query<T>
works, suppose the datastore contains million records, will Query
load all Car
objects into the memory or it will fetch it one by one from the datastore? 如何
Query<T>
的作品,假设数据存储包含百万条记录,将Query
加载所有Car
对象到内存或将取回一个一个从数据存储?
The default chunk size is 30 - see here . 默认的块大小为30-参见此处 。 Prefetch size is not set so it defaults to chunk size.
未设置预取大小,因此默认为块大小。
So, iterator will fetch 30 Entities at a time. 因此,迭代器一次将获取30个实体。
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