Difference between Solr Facet Fields and Filter Queries - solr

I am using SolrMeter to test Apache Solr search engine. The difference between Facet fields and Filter queries is not clear to me. SolrMeter tutorial lists this as an exapmle of Facet fields :
content
category
fileExtension
and this as an example of Filter queries :
category:animal
category:vegetable
categoty:vegetable price:[0 TO 10]
categoty:vegetable price:[10 TO *]
I am having a hard time wrapping my head around it. Could somebody explain by example? Can I use SolrMeter without specifying either facets or filters?

Facet fields are used to get statistics about the returned documents - specifically, for each value of that field, how many returned documents have that value for that field. So for example, if you have 10 products matching a query for "soft rug" if you facet on "origin," you might get 6 documents for "Oklahoma" and 4 for "Texas." The facet field query will give you the numbers 6 and 4.
Filter queries on the other hand are used to filter the returned results by adding another constraint. The thing to remember is that the query when used in filtering results doesn't affect the scoring or relevancy of the documents. So for example, you might search your index for a product, but you only want to return results constrained by a geographic area or something.

A facet is an field (type) of the document, so category is the field. As Ansari said, facets are used to get statistics and provide grouping capabilities. You could apply grouping on the category field to show everything vegetable as one group.
Edit: The parts about searching inside of a specific field are wrong. It will not search inside of the field only. It should be 'adding a constraint to the search' instead.
Performing a filter query of category:vegetable will search for vegetable in the category field and no other fields of the document. It is used to search just specific fields rather than every field. Sometimes you know that the term you want only is in one field so you can search just that one field.

Related

Amazon like refined filtering in solr

We need to implement drill down search like Amazon.
If any supplier is selected then,
currently it disabled rest of suppliers as solr facet only returns that selected filter.
query: supplier:supplierId
Though above query retuns multiple Screen Color/Screen Size, but on further selection, only the selected element is returned per filter section.
Any help to make it work like Amazon.com 's refined filtering will be much appreciated.
To provide multi-select faceting, you need to tag the filter involved so that you can exclude it when faceting on the corresponding field. This can be achieved using both the tag and ex local parameters.
Solr Ref Guide - Tagging and Excluding Filters :
To implement a multi-select facet for a given field, a GUI may want to still
display the other field values and their associated counts, as if
the corresponding filter constraint had not yet been applied.
To return counts for the field values that are currently not selected,
tag filters that directly constrain the field, and exclude those
filters when faceting on it.
For example, for a query that would originally look like :
q=mainquery&fq=supplier:supplierId&facet=true&facet.field=supplier
You would do the following :
q=mainquery&fq={!tag=sup}supplier:supplierId&facet=true&facet.field={!ex=sup}supplier

Hybris: Combine different solr facet under one

I have applied solr facet on properties of products.
Eg: The product can be either Medicine(0/1) or Drug(0/1) or Poison(0/1).
0 means NO, 1 means YES.
These are different features of a product hence appear as different facets. It is possible to display them under one facet instead eg: "Type", under which these three solr facet "Medicine", "Drug", "Poison" should display like:
Type
-----
Medicine (50)
Drug (100)
Poison (75)
Not sure about Hybris, but you should be able to do so with facet queries. You would have one facet query per each of your three conditions. In the UI, you can organize the counts anyway you want.
However, I am not sure why you can't just have a category field that contains a multi-valued field that contains Medicine and/or Drug and/or Poison value. Then faceting on that field would give you the breakdowns. If your values do not come in that way, you can probably manipulate them either with copyField or with a custom Update Request Processor chain to merge into one field.
This is super easy. Just make an IndexedProperty "Type" and a new custom ValueProvider for it. Then extract these values based on the boolean flags - just hard code if necessary. No need for anything more complex.
I tried the solutions posted here but they were not fitting my requirement. I did changes through facet navigation tag files to bring all classification attribute facets (Medicine, Drug, Poison) under a single facet (Type).

dynamic fields as facet in solr

I am trying to develop a filter system using dynamic fields in solr. These dynamic fields may vary from product to product and have a prefix attribute_filter_ to help me recognize the filter field. So given a search query, I want to get faceted results based on these dynamic fields.
For example, I have 3 products as docs in solr
{ID:1, attribute_filter_color:"white", attribute_filter_brand:"Dell"}
{ID:2, attribute_filter_color:"red", attribute_filter_category:"electronics"}
{ID:3, attribute_filter_size:"mobiles", attribute_filter_brand:"samsung"}
When my search query matches doc 1 and doc2, I want only filters color, brand and category and so facet fields are attribute_filter_color, attribute_filter_brand and attribute_filter_category.
When my search query matches doc 2 and doc3, I want filters color, size, category and brand and so facet fields are attribute_filter_color, attribute_filter_size, attribute_filter_category and attribute_filter_brand.
When my search query matches doc 1 and doc3, I want filters color, brand and size and so facet fields are attribute_filter_color,attribute_filter_brandand attribute_filter_size.
Also these filters can be ~300 total over 10^5 products. This creates another problem for making a GET URL with 300 facet fields which might cross the limit for GET URL.
This jira ticket shows how regex could have helped in this situation.
My solution would be to index the field names to an additional field, so that you have "facet_fields": ["attribute_filter_color","attribute_filter_brand"] for the documents containing the fields as well.
Generate a facet across your document result set, then use that result in a new query to generate facets across the fields you're interest in. It will be an extra query, but should scale decently. The part that will be expensive will be the larger number of different fields you're faceting on anyway - the facet_fields field will be quick to calculate and return.

Solr: How to get Facets with matching keywords

I am not sure if this is possible or what's the best way to do it? How can I get facet count in Solr where it counts as in following example.
Let's say I have got following values equal to the number of times they repeat in a field..
Tv = 100
Sony Tv = 10
LG Tv=10
Nokia Mobile= 5
iPhone Mobile = 4
If a user query is 'tv & mobile'. Based on above values in a field, How can I get the facets like...
Tv (120)
Mobile (9)
Based on the comment you gave to Jayendra's answer, you want to leverage Solr MultiValued fields to store those values and then facet on that multiValued field. This would give you the behavior you want for faceting.
Additionally, if you want to limit the facet results to a specific set of values, you will to supply a facet.query along with your request to Solr.
You can index the data in hierarchy form and use Solr Pivots to implement this facet.
e.g. tv/sony, tv/LG, mobile/Nokia & mobile/iPhone
This would help you to facet over parent and further drill down on the same.

Solr filter queries and boosting

Is it possible to boost fields that appear in filter queries (fq=) in Solr?
I have a faceted query that has a tagged filter query something like this:
...&q=*:*&fq={!tag:X}brand:(+"4911")+OR+body:(abc)&facet.field={!ex:X}brand&..
(I facet on brand and the facet is set to ignore the filter query tagged X, so I need to use a filter query.)
I would like to make matches on the brand field score higher than matches on body field in the filter query.
The fields brand and body are multivalued.
I've tried adding bf=/bq= arguments, and I can get brand matches to score higher if I change the filter query to be the main 'q=' query, but I don't seem to be able to influence the score of anything in the filter query. I think I maybe going about it in the wrong way..
Thanks.
Solr "fq"'s do not affect score -- see the wiki. So, you should add your queries to "q" that you actually want to boost. If need be, you can always duplicate a query restriction in both "q" and "fq", as "fq" only acts as a restriction on the results set.

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