I thought examine is now configured in code. The documentation is not yet done as you can see here: https://our.umbraco.com/Documentation/v8documentation

I would look for components with examine in the name in the source code for now.

Try this thread:

https://our.umbraco.com/forum/umbraco-8/95915-umbraco-8-examine-indexes#comment-303736

I had the same question. But for the time being, I used the default configured external indexes. In my Umbraco 8 test project, this partial snippet is used for searching content of document type "Quotation":

// q = search string from an input field
// Break search into separate terms
// You should check for null or empty string

var _searchTerms = q.Trim().Split(new char[] { ' ' }, StringSplitOptions.RemoveEmptyEntries);

// I use a loop here so I can optionally remove noise words and such...
foreach (var term in _searchTerms)
{
    searchTerms.Add(term);
}

if (searchTerms.Length > 0)
{
    if (!ExamineManager.Instance.TryGetIndex("ExternalIndex", out var index) || !(index is IUmbracoIndex umbIndex))
    { 
        throw new InvalidOperationException($"No index found by name ExternalIndex or is not of type {typeof(IUmbracoIndex)}");
    }

    var searcher = umbIndex.GetSearcher();

    if (searcher != null)
    {
        var qry = searcher.CreateQuery("", BooleanOperation.And)
            .Field("__NodeTypeAlias", "quotation");

        foreach (var term in searchTerms)
        {
            qry = qry.Or().Field("quote", term);
        }

        var results = qry.Execute(10);

        if (results != null && results.Count() > 0)
        {
            // Process results
        }
    }
}

Hope this helps while they rework the documentation ;)

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