Azure Cognitive Search prefix searching as single token

Question

I'm trying to create an Azure Search index with a searchable Name field that should not be tokenized and be treated as a single string.

So if I have two values:

• "Total Insurance"
• "Invoice Total"

With a search term like this: search=Total*, then only "Total Insurance" should be returned because it starts with "Total".

My assumption was that the 'keyword' analyzer is to be used for this type of search

https://learn.microsoft.com/en-us/azure/search/index-add-custom-analyzers#built-in-analyzers

But it doesn't seem to work like that, it doesn't return any results with search=Total*.

Is there a different setup for this type of search?

Answer 1

Something like this is required:

{   
    "name":"myIndex",
    "fields": [
        { 
            "name":"Name", 
            "type":"Edm.String", 
            "searchable":true, 
            "filterable": true, 
            "retrievable": true, 
            "sortable": true, 
            "searchAnalyzer":"keyword", 
            "indexAnalyzer":"prefixAnalyzer" 
        }   
    ],
    "analyzers": [
        {
            "name":"prefixAnalyzer",
            "@odata.type":"#Microsoft.Azure.Search.CustomAnalyzer",
            "tokenizer":"keyword_v2",
            "tokenFilters":[ "lowercase", "my_edgeNGram" ]
        }
    ],
    "tokenFilters": [
        {
            "name":"my_edgeNGram",
            "@odata.type":"#Microsoft.Azure.Search.EdgeNGramTokenFilterV2",
            "minGram":3,
            "maxGram":7
        }
    ]
}