Apache Solr Reference Guide Covering Apache Solr 6.0

aggregated into single hit into parent with
id=1. The key components of the request are:
url part
/bjqfacet
q={!parent ...}..
child.facet.field=...
meaning
The name of the request handler that has been defined with one of block join
facet components enabled.
The mandatory parent query as a main query. The parent query could also be a
subordinate clause in a more complex query.
The child document field, which might be repeated many times with several
fields, as necessary.
Highlighting
Highlighting in Solr allows fragments of documents that match the user's query to be included with the query
response. The fragments are included in a special section of the response (the highlighting section), and the
client uses the formatting clues also included to determine how to present the snippets to users.
Solr provides a collection of highlighting utilities which allow a great deal of control over the fields fragments are
taken from, the size of fragments, and how they are formatted. The highlighting utilities can be called by various
Request Handlers and can be used with the DisMax, Extended DisMax, or standard query parsers.
There are three highlighting implementations available:
Standard Highlighter: The Standard Highlighter is the swiss-army knife of the highlighters. It has the
most sophisticated and fine-grained query representation of the three highlighters. For example, this
highlighter is capable of providing precise matches even for advanced queryparsers such as the surroun
d parser. It does not require any special datastructures such as termVectors, although it will use them if
they are present. If they are not, this highlighter will re-analyze the document on-the-fly to highlight it. This
highlighter is a good choice for a wide variety of search use-cases.
FastVector Highlighter: The FastVector Highlighter requires term vector options ( termVectors,
termP
ositions, and termOffsets) on the field, and is optimized with that in mind. It tends to work better for
more languages than the Standard Highlighter, because it supports Unicode breakiterators. On the other
hand, its query-representation is less advanced than the Standard Highlighter: for example it will not work
well with the surround parser. This highlighter is a good choice for large documents and highlighting text
in a variety of languages.
Postings Highlighter: The Postings Highlighter requires storeOffsetsWithPositions to be
configured on the field. This is a much more compact and efficient structure than term vectors, but is not
appropriate for huge numbers of query terms (e.g. wildcard queries). Like the FastVector Highlighter, it
supports Unicode algorithms for dividing up the document. On the other hand, it has the most coarse
query-representation: it focuses on summary quality and ignores the structure of the query completely,
ranking passages based solely on query terms and statistics. This highlighter a good choice for classic
full-text keyword search.
Configuring Highlighting
The configuration for highlighting, whichever implementation is chosen, is first to configure a search component
and then reference the component in one or more request handlers.
The exact parameters for the search component vary depending on the implementation, but there is a robust
example in the solrconfig.xml used in the " techproducts" example which shows how to configure both
the Standard Highlighter and the FastVector Highlighter (see the Postings Highlighter section for details on how
to configure that implementation).
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