How to reduce the query quota in App engine?

Question

The user will browse (paging) sorted entities in Datastore 12 at time.

 DatastoreService datastore = DatastoreServiceFactory.getDatastoreService();

//get url parameter
int next = Integer.parseInt(request.getParameter("next") );
//query with sort
Query query = new Query("page").addSort("importance", SortDirection.DESCENDING );
PreparedQuery pq = datastore.prepare(query);

//get 12 entity from query result from the index (next)
FetchOptions options = FetchOptions.Builder.withLimit(12).chunkSize(12).offset(next);

for (Entity result : pq.asIterable(options)) {
    Text text = (Text)result.getProperty("content");
    Document doc = Jsoup.parse(text.getValue());

    //display the content
    .....
}

The problem is that when the next variable increase the quota consume increase faster!.

For example when the next is 6000, the quota consumed by 40%, while when the next is 10 the quota consumed by less than 1%.

Answer 1

If you you use the Google App Engine cursors to facilitate your paging then your queries will be optimized. It is not recommended to use large offsets. The recommended way to do paging in GAE is with cursors.