Solr：如何使用关键字列表获取按分数排序的所有文档？

Question

I have a Solr 3.1 database containing Emails with two fields:

• datetime
• text

For the query I have two parameters:

• date of today
• keyword array("important thing", "important too", "not so important, but more than average")

Is it possible to create a query to

1. get ALL documents of this day AND
2. sort them by relevancy by ordering them so that the email with contains most of my keywords(important things) scores best?

The part with the date is not very complicated:

fq=datetime[YY-MM-DDT00:00:00.000Z TO YY-MM-DDT23:59:59.999Z]

I know that you can boost the keywords this way:

q=text:"first keyword"^5 OR text:"second one"^2 OR text:"minus scoring"^0.5 OR text:"*"

But how do I only use the keywords to sort this list and get ALL entries instead of doing a realy query and get only a few entries back?

Thanks for help!

Answer 1

You could do a first query for:

fq=datetime[YY-MM-DDT00:00:00.000Z TO YY-MM-DDT23:59:59.999Z]

which gives all documents that match the range. Then, use CachingWrapperFilter for the second query to find documents in the DocSet from first query which have at least one keyword. They will be relevance ranked per tf-idf. You may want to use ConstantScoringQuery for the first to get the list of matching docids in the fastest possible way.

Answer 2

You need to specify your terms in the main query and then change your date query to be a filter query on these results by adding the following.

fq=datetime[YY-MM-DDT00:00:00.000Z TO YY-MM-DDT23:59:59.999Z]

So you should have something like this:

q=<terms go here>&fq=datetime[YY-MM-DDT00:00:00.000Z TO YY-MM-DDT23:59:59.999Z]

Edit: A little more about filter queries (as suggested by rfreak ).

From Solr Wiki - FilterQuery Guidance - "Now, what is a filter query? It is simply a part of a query that is factored out for special treatment. This is achieved in Solr by specifying it using the fq (filter query) parameter instead of the q (main query) parameter. The same result could be achieved leaving that query part in the main query. The difference will be in query efficiency. That's because the result of a filter query is cached and then used to filter a primary query result using set intersection."

These should be sorted by relevancy score already, that is just the default behavior of Solr. You can see the score by adding that field.

fl=*,score

If you use the Full Interface for Make A Query on the Admin Interface on your Solr installation at http://<yourserver:port#>/<instancename>/admin/form.jsp you will see where you can specify the filter query, fields, and other options. You can check out the Solr Wiki for more details on the options and how they are used.

I hope that this helps you.

Answer 3

Sorting by relevance is default behavior on solr/lucene.

If your results are unsatisfied, try to put the keywords in quotes

//Edit: Folowing the answer from Paige Cook, use somethink like that

q="important thing"&fq=datetime[YY-MM-DDT00:00:00.000Z TO YY-MM-DDT23:59:59.999Z]

//2. nd update. By thinking about this answer: quotes are not an good idea, because in this case you will only receive "important thing" mails, but no "important too"

The Point is: what keywords you are using. Because: searching for -- important thing -- results in the highest scores for "important thing" mails. But lucene does not know, how to score "important too" or "not so important, but more than average" in relation to your keywords. An other idea would be searching only for "important". But the field-values "importand thing" and "importand too" gives nearly the same score values,because 50% of the searched keywords (in this key: "imported") are part of the field-value. So probably you have to change your keywords. It could work after changeing "importend to" into "also an important mail", to get the beast ratio of search-word "important" and field-value in order to score the shortest Mail-discripton to the highest value.