On Sun, Jan 20, 2013 at 11:12 PM, Chris Rohr <[email protected]> wrote:
> Hi everyone,
>
> First time poster here but have been using 0.1.x for quite a while. I've
> gotten 0.2 up and running and I had a couple of implementation questions.
>
> 1. Can you explain how the session object in the thrift interface is
> supposed to be used?
>
The session object creates a snapshot of the indexes during a search and
fetch of the documents. Because search and fetch are 2 different calls
this ensures that the document id can not change during searching.
(Document ids can change from Lucene generation to generation)
>
> 2. Is the SimpleQuery concept from 0.1.x gone in 0.2?
>
No, it's still possible. I have included some sample code below.
>
> 3. If I was to use CDH, which version is recommended for 0.2?
>
CDH3 is the only version that Blur has been tested with, use the lastest
update from Cloudera if you are using CDH3. I think that update 5 (CDHu5)
is the latest.
>
> Thank you in advance,
> Chris
// This takes the place of simple query
Query query = new Query();
query.setType(QueryType.STRING);
query.setQueryString(queryStr);
QueryArgs queryArgs = new QueryArgs();
queryArgs.setQuery(query);
// This tells the server to only return a single TopFieldDocs in the search
call
// instead of a TopFieldDocs object per shard in the table. NOTE: I can't
// remember if I've actually written the aggregate function.
queryArgs.setAggregateResults(true);
// Creates a snapshot of the indexes
Session session = client.openReadSession(tablename);
// Runs the search
List<TopFieldDocs> topDocs = client.search(session, queryArgs);
// Gets the document locations form the TopFieldDocs
TopFieldDocs topFieldDocs = topDocs.iterator().next();
List<Long> docLocations = BlurThriftUtil.toDocLocations(topFieldDocs);
// This fetches all of the documents with all their fields.
List<Document> docs = client.doc(session, docLocations, null);
long totalHits = topFieldDocs.getTotalHits();
out.println("Totalhits " + totalHits);
print(docs, docLocations, showDocLocations, showBoost, showType, out,
maxLineWidth);
// Closes the session.
client.closeReadSession(session);
