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# Online Documentation of Functions

You can get online Help for the Hive extension functions by using this command:

    DESCRIBE FUNCTION [EXTENDED] function_name;

This example provides a brief description of the `xml_query` function:

    hive> describe function xml_query;
    OK
    xml_query(query, bindings) - Returns the result of the query as a STRING array

The `EXTENDED` option provides a detailed description and examples:

    hive> describe function extended xml_query;
    OK
    xml_query(query, bindings) - Returns the result of the query as a STRING array
    Evaluates an XQuery expression with the specified bindings. The query argument must be a STRING and the bindings argument must be a STRING or a STRUCT. If the bindings argument is a STRING, it is parsed as XML and bound to the initial context item of the query. For example:

      > SELECT xml_query("x/y", "<x><y>hello</y><z/><y>world</y></x>") FROM src LIMIT 1;
      ["hello", "world"]
         .
         .
         .