actually all i had to do was use an equality filter
query.addFilter("feeds", FilterOperator.EQUALS, feed.getId());
On Sep 21, 2:35 am, siliconeagle <[email protected]> wrote:
> I have an appengine app which has been running for about a year now, i
> have mainly been using JDO queries until now, but i am trying to
> collect stats and the queries are taking too long. I have the
> following entity (Device)
>
> public class Device implements Serializable{
> ...
> @Persistent
> private Set<Key> feeds;// Key for the Feed entity
> ...}
>
> So I want to get a count of how many Devices have a certain Feed. I
> was doing it in JDOQL before as such (uses javax.jdo.Query):
>
> Query query = pm.newQuery("select from Device where
> feeds.contains(:feedKey)");
> Map<String, Object> paramsf = new HashMap<String, Object>();
> paramsf.put("feedKey",feed.getId());
> List<Device> results = (List<Device>) query.executeWithMap(paramsf);
> Though this code times out now. I was trying to use the Datastore API
> so I could set chunk size,etc to see if i could speed the query up or
> use a cursor, but I am unsure how to search in a Set field. I was
> trying this (uses com.google.appengine.api.datastore.Query)
>
> Query query = new Query("Device");
> query.addFilter("feeds", FilterOperator.IN, feed.getId());
> query.setKeysOnly();
> final FetchOptions fetchOptions =
> FetchOptions.Builder.withPrefetchSize(100).chunkSize(100);
> QueryResultList<Entity> results =
> dss.prepare(query).asQueryResultList(fetchOptions);
> Essentially i am unsure how to search in the one-to-many filed (feeds)
> for a single key. Is it possible to index it somehow?
>
> hope it makes sense....
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