Develop Reference

In AEM query builder order by based on someproperty=somevalue

I m trying to sort the AEM query builder search results based on particular value of particular property. as we have in any database like MySQL we can sort based on column's value as well (for exp. ORDER BY FIELD('columnName','anyColumnName'). can we have something like this in AEM.
Suppose we have 5 Assets under path /content/dam/Assets.
Asset Name------------dc:title
1.jpg------------------Apple
2.jpg------------------Cat
3.jpg------------------Cat
4.jpg------------------Ball
5.jpg------------------Drag
I need assets on top of the results where dc:title = cat and also need other results also in sorting asc. expected result as given below
2.jpg------------------Cat
3.jpg------------------Cat
1.jpg------------------Apple
4.jpg------------------Ball
5.jpg------------------Drag
Note:- Using version AEM 6.2

You can use the orderby predicate with a value of #jcr:content/metadata/dc:title to sort by dc:title with the QueryBuilder. /libs/cq/search/content/querydebug.html is an interface to test queries on your instance. ACS Commons has a good breakdown of all out of the box predicates
If you want to pull Cats to the top of the results with a single query, you could write a custom predicate. The sample code from ACS Commons shows an example. Adobe has documentation as well.

Explanation on the "Rank" for Retrieve & Rank service in Java

Does anyone ever used the Retrieve & Rank service with Java SDK (Rank service particularly) ?
I want to understand how it works because some points seem me not logical :
What is the difference between the Java approach, where we must execute a search query with Apache Solr, and then call the method rank; and the CURL approach, where we just have to run a single query?
Why the method rank takes a CSV file that contains results from the search query whereas we apparently cannot have the result of a search query in CSV?
I did not find my responses neitheir in this documentation nor in this example.
Thanks for your time.

I have never used Retrieve and Rank before but by reading the documentation here are my thoughts
I do not think that there any difference between Java approach and CURL. From what I understand Search and rank in curl uses this command
curl -u "{username}":"{password}" "https://gateway.watsonplatform.net/retrieve-and-rank/api/v1/solr_clusters/sc1ca23733_faa8_49ce_b3b6_dc3e193264c6/solr/example_collection/fcselect?ranker_id=B2E325-rank-67&q=what%20is%20the%20basic%20mechanism%20of%20the%20transonic%20aileron%20buzz&wt=json&fl=id,title"
while in Java
RetrieveAndRank service = new RetrieveAndRank();
service.setUsernameAndPassword("{username}","{password}");
HttpSolrClient solrClient = new HttpSolrClient;
solrClient = getSolrClient(service.getSolrUrl("scfaaf8903_02c1_4297_84c6_76b79537d849"), "{username}","{password}");
SolrQuery query = new SolrQuery("what is the basic mechanism of the transonic aileron buzz");
QueryResponse response = solrClient.query("example_collection", query);
Ranking ranking = service.rank("B2E325-rank-67", response);
System.out.println(ranking);
I think what the curl command would do, at the back end it would fire a search in Solr using the query specified and after the results returned it would rank them.
In Java this is done explicitly, instead of having a method queryAndRank you have two methods, one that is going to run in Solr, get the results from there and then forward these results to ranking system.
The search in Solr can return csv.
The CSVResponseWriter can write the list of documents in a response in
CSV format.
http://wiki.apache.org/solr/CSVResponseWriter

Save the result set of a query against a view to a table using the java client library

Recently, one of our clients reported not being able to create a table based on a query against a view. That said, they were able to save the result of a query against a table into another table. This issue spawned a more implementation focused question using the Java client libraries. Specifically, is there any way to save the result set of a query against a view to a table using the Java client library? I will be digging and post anything that I find. That said, any early guidance would be appreciated!
To be specific and add more context, I note that the the following process failed when the query was run against a union view.
java -jar BigQueryToCloudExporter.jar ./GAFastAccessKey.p12 '' "
Select date(date_add('2014-08-09',floor(datediff(date(sec_to_timestamp(visitstarttime)),'2014-08-03')/7)*7,"DAY")) WeekEndDate
, hits.eventinfo.eventaction GA_RentalNo
, count(distinct visitID) PDP_PPC
FROM (TABLE_DATE_RANGE([Union_View.GA],
TIMESTAMP('2014-08-30'),
TIMESTAMP('2014-09-13')))
where hits.eventinfo.eventcategory='property attributes'
and brandId=121
--hits.eventinfo.eventcategory='property inquiry'
and trafficsource.medium like '%cpc%'
--and trafficsource.campaign not like '%ppb%'
and trafficsource.campaign like '%mpm%'
group each by WeekEndDate, GA_XXXXXX
order by WeekEndDate, GA_XXXXXX limit 100" StagingQueryTable QueryTable AVRO gs://XXXXXX/QueryTable*.avro
On the other hand, the following process succeeded when the query was made against a BigQuery table (keeping everything else same).
java -jar BigQueryToCloudExporter.jar ./GAFastAccessKey.p12 '' "
Select date(date_add('2014-08-09',floor(datediff(date(sec_to_timestamp(visitstarttime)),'2014-08-03')/7)*7,"DAY")) WeekEndDate
, hits.eventinfo.eventaction GA_XXXXXX
, count(distinct visitID) PDP_PPC
FROM (TABLE_DATE_RANGE([XXXXXX.ga_sessions_],
TIMESTAMP('2014-08-30'),
TIMESTAMP('2014-09-13')))
where hits.eventinfo.eventcategory='property attributes'
and brandId=121
--hits.eventinfo.eventcategory='property inquiry'
and trafficsource.medium like '%cpc%'
--and trafficsource.campaign not like '%ppb%'
and trafficsource.campaign like '%mpm%'
group each by WeekEndDate, GA_RentalNo
order by WeekEndDate, GA_XXXXXX limit 100" StagingQueryTable QueryTable AVRO gs://XXXXXX/QueryTable*.avro

Archiving a mongodb collection

I'm using java Spring and spring data for mongodb.
I have a collection that needs to contain only documents from the last 3 months but all the documents should be saved in some way (maybe expoet to a file?). I'm looking for solution but all i can find talks about full DB backup.
What is the best way to keep the collection updated to only the last 3 months? (weekly cron?)
How to save the collection archive? I think mongodump is an overkill.

Both mongoexport and mongodump support a -q option to specify a query to limit the documents that will be deleted. The choice for either is more of a function of what format you'd like the data to be stored in.
Let's assume that you have a collection with a timestamp field. You could run either one of these (filling in the required names and times in the angle brackets):
mongoexport -d <yourdatabase> -c <yourcollection> -q "{ timestamp: { \$gt: <yourtimestamp>}}" -o <yourcollection_export_yourtimestamp>.json
mongodump -d <yourdatabase> -c <yourcollection> -q "{ timestamp: { \$gt: <yourtimestamp>}}"
And then delete the old data.
Alternatively you could take periodic snapshots via cron with either method on a collection with a ttl index so that you don't have to prune it yourself - mongodb will automatically delete older data:
db.collectioname.ensureIndex( { "createdAt": 1 }, { expireAfterSeconds: 7862400 } )
This will keep deleting any document older than 91 days based on a createdAt field in the document
http://docs.mongodb.org/manual/tutorial/expire-data/

With mongoexport you can backup a single collection instead of the whole database. I would recommand a Cron-Job (like you sad) to export the data and ceep the database limited to the Documents of the last 3 months my removing oder documents.
mongoexport -d databasename -c collectionname -o savefilename.json

Mongo DB, Java Mongo API, how to add hint into aggregate command

I stuck with Mongo with $hint command.
I have collection and i had indexed this collection. But the problem is, I query collection with Aggregate framework, but I want temporary disable Indexing, so I use hint command like this:
db.runCommand(
{aggregate:"MyCollectionName",
pipeline:[{$match : {...somthing...},
{$project : {...somthing...}}]
},
{$hint:{$natural:1}}
)
Please Note that I use {$hint:{$natural:1}} to disable Indexing for this query,
I have run SUCCESSFULLY this command on MongoDB command line. But I don't know how to map this command to Mongo Java Api (Java Code).
I used lib mongo-2.10.1.jar

Currently you can't - it is on the backlog - please vote for SERVER-7944