I've built an index with a Custom Analyzer
"analyzers": [
{
"#odata.type": "#Microsoft.Azure.Search.CustomAnalyzer",
"name": "ingram",
"tokenizer": "whitespace",
"tokenFilters": [ "lowercase", "NGramTokenFilter" ],
"charFilters": []
}
],
"tokenFilters": [
{
"#odata.type": "#Microsoft.Azure.Search.NGramTokenFilterV2",
"name": "NGramTokenFilter",
"minGram": 3,
"maxGram": 8
}
],
I came upon Suggesters and was wondering what the pros/cons were between these 2 approaches.
Basically, I'm doing an JavaScript autocomplete text box. I need to do partial text search inside of the search text (i.e. search=ell would match on "Hello World".
Azure Search offers two features to enable this depending on the experience you want to give to your users:
- Suggestions: https://learn.microsoft.com/en-us/rest/api/searchservice/suggestions
- Autocomplete: https://learn.microsoft.com/en-us/rest/api/searchservice/autocomplete
Suggestions will return a list of matching documents even with incomplete query terms, and you are right that it can be reproduced with a custom analyzer that uses ngrams. It's just a simpler way to accomplish that (since we took care of setting up the analyzer for you).
Autocomplete is very similar, but instead of returning matching documents, it will simply return a list of completed "terms" that match the incomplete term in your query. This will make sure terms are not duplicated in the autocomplete list (which can happen when using the suggestions API, since as I mentioned above, suggestions return matching documents, rather than a list of terms).
Related
We split the user-query on ascii spaces to create a weakAnd(...).
The user-input "Watch【Docudrama】" does not contain a whitespace - but throws an error.
Question: Which codepoints beside whitespaces should be used to split the query?
YQL (fails):
select * from post where text contains "Watch【Docudrama】" limit 1;
YQL (works):
select * from post where weakAnd(text contains "Watch",text contains "【Docudrama】") limit 1;
Error message:
{
"root": {
"id": "toplevel",
"relevance": 1,
"fields": {
"totalCount": 0
},
"errors": [
{
"code": 4,
"summary": "Invalid query parameter",
"source": "content",
"message": "Can not add WORD_ALTERNATIVES text:[ Watch【Docudrama】(1.0) watch(0.7) ] to a segment phrase"
}
]
}
}
Are you sure you need to use WAND for this? Try setting the user query grammar to "any" (default is "all"), which will use the "OR" operator for user supplied terms. There is an example here: https://docs.vespa.ai/documentation/reference/query-language-reference.html#userinput
The process of splitting up the query is known as Tokenization. This is a complex and language dependent process, Vespa uses Apache OpenNLP to do this (and more): https://docs.vespa.ai/documentation/linguistics.html has more information and also references to the code which performs this operation.
If you really want to use WAND, instead of reimplementing the query parsing logic outside Vespa, I suggest you create a Java searcher which descends the query tree and modifies it by replacing the created AndItem with WeakAndItem. See https://docs.vespa.ai/documentation/searcher-development.html and the code example here: https://docs.vespa.ai/documentation/advanced-ranking.html
In my instance of Solr 4.10.3 I would like to index JSONs with a nested structure.
Example:
{
"id": "myDoc",
"title": "myTitle"
"nestedDoc": {
"name": "test name"
"nestedAttribute": {
"attr1": "attr1Val"
}
}
}
I am able to store it correctly through the admin interface:
/solr/#/mySchema/documents
and I'm also able to search and retrieve the document.
The problem I'm facing is that when I get the response document from my Solr search, I cannot see the nested attributes. I only see:
{
"id": "myDoc",
"title": "myTitle"
}
Is there a way to include ALL the nested fields in the returned documents?
I tried with : "fl=[child parentFilter=title:myTitle]" but it's not working (ChildDocTransformerFactory from:https://cwiki.apache.org/confluence/display/solr/Transforming+Result+Documents). Is that the right way to do it or is there any other way?
I'm using: Solr 4.10.3!!!!!!
To get returned all the nested structure, you indeed need to use ChildDocTransformerFactor. However, you first need to properly index your documents.
If you just passed your structure as it is, Solr will index them as separate documents and won't know that they're actually connected. If you want to be able to correctly query nested documents, you'll have to pre-process your data structure as described in this post or try using (modifying as needed) a pre-processing script. Unfortunately, including the latest Solr 6.0, there's no nice and smooth solution on indexing and returning nested document structures, so everything is done through "workarounds".
Particularly in your case, you'll need to transform your document structure into this:
{
"type": "parentDoc",
"id": "myDoc",
"title": "myTitle"
"_childDocuments_": [
{
"type": "nestedDoc",
"name": "test name",
"_childDocuments_" :[
{
"type": "nestedAttribute"
"attr1": "attr1Val"
}]
}]
}
Then, the following ChildDocTransformerFactor query will return you all subdocuments (btw, although it says it's available since Solr 4.9, I've actually only seen it in Solr 5.3... so you need to test):
q=title:myTitle&fl=*,[child parentFilter=type:parentDoc limit=50]
Note, although it returns all nested documents, the returned document structure will be flattend (alas!), i.e., you'll get:
{
"type": "parentDoc",
"id": "myDoc",
"title": "myTitle"
"_childDocuments_": [
{
"type": "nestedDoc",
"name": "test name"
},
{
"type": "nestedAttribute"
"attr1": "attr1Val"
}]
}
Probably, not really what you've expected but... this is the unfortunate Solr's behavior that will be fixed in a nearest future release.
You can put
q={!parent which=}
and in fl field :"fl=*,[child parentFilter=title:myTitle].
It will give you all parent field and children field of title:mytitle
The suggester in Azure Search has only 1 SearchMode and that is it will match on any word within the field. Although this might be appropriate for many applications, it also is not for many others.
Is there any way we can configure the suggester so that a match occurs only when the beginning of the field is a match?
Many thanks for your assistance.
Consider creating a custom analyzer that at index time generates prefixes of words from your documents:
{
"name":"names",
"fields": [
{ "name":"id", "type":"Edm.String", "key":true, "searchable":false },
{ "name":"partialName", "type":"Edm.String", "searchable":true, "searchAnalyzer":"standard", "indexAnalyzer":"prefixAnalyzer" }
],
"analyzers": [
{
"name":"prefixAnalyzer",
"#odata.type":"#Microsoft.Azure.Search.CustomAnalyzer",
"tokenizer":"standard",
"tokenFilters":[ "lowercase", "my_edgeNGram" ]
}
],
"tokenFilters": [
{
"name":"my_edgeNGram",
"#odata.type":"#Microsoft.Azure.Search.EdgeNGramTokenFilter",
"minGram":2,
"maxGram":20
}
]
}
Notice the partialName field uses the standard analyzer for search and the custom (prefixAnalyzer) analyzer for indexing. You can now issue regular Search requests with prefixes of words as query terms.
You can learn more about the EdgeNGramTokenFilter from our documentation page about Analysis in Azure Search.
Let me know if this helps.
Currently only infix matching is supported in suggestions.
Is it possible to define which part of the text in which of the indexed text fields matches the query?
No, as far as I know and can tell from the Jira, no such feature exists currently. You can, of course, attempt to highlight the parts of the text yourself, but that requires to implement the highlighting and also implement the stemming according to the rules applied by MongoDB.
The whole feature is somewhat complicated - even consuming it - as can be seen from the respective elasticsearch documentation.
Refer to Mongodb Doc Highlighting
db.fruit.aggregate([
{
$searchBeta: {
"search": {
"path": "description",
"query": ["variety", "bunch"]
},
"highlight": {
"path": "description"
}
}
},
{
$project: {
"description": 1,
"_id": 0,
"highlights": { "$meta": "searchHighlights" }
}
}
])
I'm afraid that solution applies only to MongoDB Atlas at the moment #LF00.
I'm pretty new to Solr, I'm trying to add a multi-value field with boost values defined for each value, all defined via JSON. In other words, I'd like this to work:
[{ "id": "ID1000",
"tag": [
{ "boost": 1, "value": "A test value" },
{ "boost": 2, "value": "A boosted value" } ]
}]
I know how to do that in XML (multiple <field name = 'tag' boost = '...'>), but the JSON code above doesn't work, the server says "Error parsing JSON field value. Unexpected OBJECT_START". Has Solr a limit/bug?
PS: I fixed the originally-missing ']' and that's not the problem.
EDIT: It seems the way to go should be payloads (http://wiki.apache.org/solr/Payloads), but I couldn't make them to work on Solr (followed this: http://sujitpal.blogspot.co.uk/2011/01/payloads-with-solr.html). Leaving the question open to see if someone can further help.
Found the following sentence in the from the Solr Relevancy FAQ - Query Elevation Component section
An Index-time boost on a value of a multiValued field applies to all values for that field.
I do not think adding an individual boost to each value in the multivalued field is going to work. I know that the Xml will allow it, but I would guess that it may only apply the boost value from the last value applied to the field.
So based on that I would change the Json to the following and see if that works.
[
{
"id": "ID1000",
"tag": {
"boost": 2,
"value": [ "A test value", "A boosted value"]
}
}
]
The JSON seems to be invalid missing a closing ]
[
{
"id": "ID1000",
"tag": [
{
"boost": 1,
"value": "A test value"
},
{
"boost": 2,
"value": "A boosted value"
}
]
}
]
You hit an edge case. You can have the boosts on single values and you can have an array of values. But not one inside another (from my reading of Solr 4.1 source code)
That might be something to create as an enhancement request.
If you are generating that JSON by hand, you can try:
"tag": { "boost": 1, "value": "A test value" },
"tag": { "boost": 2, "value": "A boosted value" }
I believe Sols will merge the values then. But if you are generating it via a framework, it will most likely disallow or override multiple object property names (tag here).
The error has nothing to do with boosting.
I get the same error with a very simple json doc.
No luck solving it.
see Solr errors when trying to parse a collection: Error parsing JSON field value. Unexp ected OBJECT_START
I hit the same error message. Actually the error message was misplaced. The underlying real error was the two of the required fields as per schema.xml in solr configuration were missing in the json payload.
An error message of the kind "required parameters are missing in the document" would have been more helpful here. You might want to check if some required fields are missing in the json payload.