Hi Any distributed lookup is basically composed of two stages: the first collecting all the matching documents from every shard and a second which fetches additional information about specific ids (i.e stored, termVectors).
It can be seen in the logs of each shard (isShard=true), where first request logs the num of hits that were received on the query by the specific shard and a second that contains the ids fields (ids=...) for the additional fetch. At the end of both I get a total QTime of the query and the total num of hits. My question is about the case only id's are requested (fl=id). This query should make only one request against a shard, while it actually does the two of them. Looks like the response builder has to go through these two stages no matter what is the kind of query. My question: 1. Is it normal the response builder has to go though both stages? 2. Does the first request gets internal lucene DocId's or the actual uniqueKey id? 3. A query as above (fl=id), where is the Id read from? Is it fetched from the stored file? or doc value file if exists? Because if fetched from the stored, a high row param (say 1000 in my case) would need 1000 lookups which could badly heart performance. Thanks Manuel
