MarkLogic 10 Product Documentationcts:similar-query
cts:similar-query( $nodes as node()*, [$weight as xs:double?], [$options as element()?] ) as cts:similar-query
Summary
Returns a query matching nodes similar to the model nodes. It uses an
algorithm which finds the most "relevant" terms in the model nodes
(that is, the terms with the highest scores), and then creates a
query equivalent to a cts:or-query of those terms. By default
16 terms are used.
| Parameters | |
|---|---|
| nodes | Some model nodes. |
| weight | A weight for this query. Higher weights move search results up in the relevance order. The default is 1.0. The weight should be between 64 and -16. Weights greater than 64 will have the same effect as a weight of 64. Weights less than the absolute value of 0.0625 (between -0.0625 and 0.0625) are rounded to 0, which means that they do not contribute to the score. |
| options |
An XML representation of
the options for defining
which terms to generate and how to evaluate them.
The options node must be in the
cts:distinctive-terms namespace. The following is
a sample options node
:
See the
Note that enabling index settings that are disabled in the database configuration will not affect the results, as similar documents will not be found on the basis of terms that do not exist in the actual database index. |
Usage Notes
As the number of fragments in a database grows, the results ofcts:similar-query
become
increasingly accurate. For best results, there should be at least 10,000
fragments for 32-bit systems, and 1,000 fragments for 64-bit systems.
Example
cts:search(//function,
cts:similar-query((//function)[1]))
=> .. relevance-ordered sequence of 'function' element
ancestors (or self) of any node similar to the first
'function' element.
Example
xdmp:estimate(
cts:search(//function,
cts:similar-query((//function)[1], (),
<options xmlns="cts:distinctive-terms">
<max-terms>20</max-terms>
<use-db-config>true</use-db-config>
</options>)))
=> the number of fragments containing any node similar
to the first 'function' element.