This document describes the functions available in X-Query. Many of them are defined in XPath with the same syntax and semantics. Please refer to the XPath specification for a more detailed description. Functions that are not present in XPath are marked with an asterisk. Some of the functions that are present in XPath are not implemented in X-Query, but you can extend the functionality of X-Query by writing server extensions implementing the desired function. These extensions can then be registered within the database server so that they are available for all further queries.

Category	Function	Short Description
Type conversion	boolean()	convert argument to a Boolean value
	number()	convert argument to a number
	string()	convert argument to a string
Arithmetic functions	ceiling()	return the smallest integer that is greater than or equal to the argument's numeric value
	floor()	return the largest integer that is less than or equal to the argument's numeric value
	round()	return the integer that is closest to the argument's numeric value
String functions	starts-with()	test whether one string starts with another string
Aggregation	avg() *	return the average value of a set of numeric values that the argument's node set contain
	count()	return the number of nodes present in the argument's node set
	min() *	return the smallest value of a set of numeric values that the argument's node set contain
	max() *	return the largest value of a set of numeric values that the argument's node set contain
	sum()	calculate the total of a set of numeric values that the argument's node set contain
Node Names	name()	return a qualified name representing the name of a node
Boolean functions	false()	return the Boolean value "false"
	not()	return the negated value of its argument
	true()	return the Boolean value "true"
Context information	last()	return the position number of the last node in the list
	position()	return the position number of the context node
Analysis	ino:explain() *	return query execution plan

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