Suppose you have millions items(say search results) and you have different parameters for sorting these items(like in eCommerce sites). We will be showing the items using pagination.
Let us say it can be sorted by date, popularity and relevance and results are paginated. How would you implement this functionality? Generally I would create different compare functions for parameters and get results accordingly.
If there any other efficient way to have this kind of functionality instead of sorting the search results every time? Also, do we generally run sql query every time using relevant order parameter or should we sort the search result of previous query to save us from re-searching time?
"If there any other efficient way to have this kind of functionality instead of sorting the search results every time?"
I would say you do not need sort every time but execute SQL query with appropriate OrderBy parameter, paginate it and show to the user
"Also, do we generally run sql query every time using relevant order parameter or should we sort the search result of previous query to save us from re-searching time?"
For sure you need to generate a new SQL query, as the first page data based on a new order parameter can contain completely different set of data from previouse one.
Related
i'm facing a big problem in my SolR DB.
My objects have a datetime field "Available_From" and a datetime field "Available_To".
We also have a "Ranking" field for the sorting.
I can search correctly with direct queries (eg. give me all the items that are available at the moment) but when i do a regular search i cannot find a way to show the items that result "available NOW" in the first places in the results, usually sorted by "Ranking" field.
How can i do this? Am I forced to write some java classes (the nearest thing i've found is there https://medium.com/#devchaitu18/sorting-based-on-a-custom-function-in-solr-c94ddae99a12) or is there a way to do with standard SolR queries?
Thanks in advance to everyone!
In your case you actually don't want sorting, since that indicates that you want one field to determine the returned sequence of documents.
Instead, use boosting - apply a very large boost to those that are available now, either through bq or boost, then apply a boost based on ranking. You'll have to tweak the weights given to each part based on how you want the search results to be presented.
I'm using Solr to run a query on one of our cores. Suppose my documents have two fields: ID, and Name. I also have a separate list of IDs I'm grabbing from a database and passing into the query to boost certain results.
If the document gets returned in the query and the ID is in the list it goes to the top of the results, and if it gets returned in the query and the ID is not in the list then it goes below those that are in the list. The former is from the "boost". My query is something like this -
http://mysolrserver:8983/solr/MyCore/MyQueryHandler?q=Smith&start=0&rows=25&bq=Id%3a(36+OR+76+OR+90+OR+224+OR+391)
I am able to get the boost query working but I need the boosted results to be in alphabetical order by name, then the non boosted results under that also in alphabetical order by name. I need to know what to user for the &sort= parameter.
&sort=score%20desc,Name+asc does not work.
I've looked over a lot of documentation, but I still don't know if this even possible. Any help is appreciated. Thanks!
Solr version is 6.0.1. I am actually using SolrNet to interface with Solr, but I think I can figure out the SolrNet part if I know what the url's &sort= parameter value needs to be.
I figured it out, by doing away with the boost query. I added a sort query using the "exists" function and passing it a sub-query for the ID. The exists returns a boolean value to sort on, then I added the name as a second sort. It works perfect!!
The URL looks like this:
http://mysolrserver:8983/solr/MyCore/MyQueryHandler?q=Smith&start=0&rows=25&sort=exists(query({!v=%27Id:(36+OR+76+OR+90+OR+224+OR+391)%27}))%20DESC,%20Name%20ASC
The closest match to your requirement is the query elevation component[1] .
In your particular case I would first sort my Ids according to my requirements ( sorting them by name for example), then maintain them in the elevate.xml.
At query time you can use the "forceElevation" parameter to force the elevation and then sort the remaining results by name.
[1] https://cwiki.apache.org/confluence/display/solr/The+Query+Elevation+Component
I want to understand how sorting works in GSA in below situations:
1) I am executing the query "Jayesh Bhoyar Autobiography" and I received 2000 records and in the query I have also mentioned sort by Date. So my understanding is GSA will pick Top 1000 records from above list based on the Relevance and then Sort it by Date?
However I want GSA should return only top 100 results for "Jayesh Bhoyar Autobiography" as per the relevance and sort on those top 100 records based on the Date. IS this possible?
If yes, how it is possible?
Regards,
Jayesh Bhoyar
The GSA can't do this by itself. If you want to do this, you can easily build a simple application that fetches the first hundred results sorted by relevance, then sorts those results by date. Use the simple XML API to fetch unformatted results from the GSA.
Search Protocol Reference
I can't find any informations on Azure Search documentation about how the results are sorted when the query sent is empty. I've also read the Empty Search section of ElasticSearch but still can't find any answer.
Is this sorting by Key?
Is the backend sending a batch of parallel requests and concatenate the results since the sorting doesn't matter?
in case of empty query, the sort order is unspecified. You cannot rely on any particular order. If you need a specific order, ask for it using orderby query parameter.
HTH,
Eugene
Search query which I send to SOLR is:
?q=iphone 4s&sort=sold desc
By default the search works great, but the problem appears when I want to
sort results by some field for eg. sold - No. of sold products.
SOLR finds all the results which have: (iphone 4s) or (iphone) or (4s)
So, when I apply sort by field 'sold' first result is: "iPhone 3GS..." which is problem.
I need the results by phrase ("iphone 4s") first and then the rest of the results - all sorted by sold.
So, the questions are:
Is it possible to have query like this, and how?
q=iphone 4s&sort={some algoritam for phrase results first} desc, sold desc
Or, can I perform this by setting up query analyzer and how?
At the moment this is solved by sending 2 requests to SOLR,
first with phrase "iphone 4s" and, if this returns 0 results,
I perform second request without the phrase - only: iphone 4s.
If sorting by score, id, field is not sufficient, Lucene lets you implement custom sorting mechanism by providing your own subclass of FieldComparatorSource abstract base class.
With in that custom-sort-logic, you can implement the way that realizes your requirements.
Example Java code:
If(modelNum1.equals(modelNum2)){
//return based on number of units sold.
}else{
//ALWAYS return a value such that the preferred model beats others.
}
DISCLAIMER: This may lead to maintenance problems as you will have to change the logic when a new phone model arrives.
Steps:
1) Sort object accepts FieldComparatorSource type instance during instantiation.
2) Extend the FieldComparatorSource
3) You've to load the required field information that participates in 'SORTING' using FieldCache within the FieldComparatorSource in setNextReader()
4) Override the FieldComparatorSource.newComparator() to return your custom FieldComparator.
5) In the method FieldComparator.compare(slot1DocId, slot2DocId), you may include your custom logic by accessing the corresponding field information, via loaded FieldCache, using the docIds passed in.
Incorporating Lucene code into Solr as a plug-in should not trouble you..
EDIT:
Can not use space in that function. Term is only without space.
As of Solr3.1, sorting can also be done on arbitrary function queries
(as in FunctionQuery) that produce a single value per document.
So, I will use function termfreq in sort
termfreq(field,term) returns the number of times the term appears in
the field for that document.
Search query will be
q=iphone 4s&sort=termfreq(product_name,"iphone 4s") desc, sold desc
Note: The function termfreq is active from Solr 4.0 version