Examples of index definitions and queries that use them

Examples demonstrate some common types of predicates that reference XML documents, and compatible indexes for those predicates.

Examples of XML index usage by equal predicates
Examples demonstrate the use of XML indexes by equal predicates.
Examples of XML index usage by predicates that test for node existence
If an XMLEXISTS predicate contains the fn:exists or fn:not function, it matches an XML index that contains the fn:exists or fn:not function.
Example of XML index usage by predicates with case-insensitive comparisons
In XML, string comparisons are case-sensitive. However, some applications might require case-insensitive comparisons. You can use the fn:upper-case function to do a case-insensitive comparison.
Example of index usage for an XMLEXISTS predicate with the fn:starts-with function
An XMLEXISTS predicate that contains the fn:starts-with function and an XML index need to meet several conditions for an index match.
Example of index usage for an XMLEXISTS predicate with the fn:substring function
An XMLEXISTS predicate that contains the fn:substring function and an XML index need to meet the several conditions for an index match.
Example of XML index usage by join predicates
If an XMLEXISTS predicate contains a join of two tables, the join condition compares two XPath expressions. An XML index that the predicate uses must be on the first table in the join order, and the XPath expression must match both XPath expressions in the join condition.
Example of XML index usage by queries with XMLTABLE
If the FROM clause of a query contains an XMLTABLE function with a row-XQuery-expression, and Db2 transforms the query to contain an XMLEXISTS predicate, after transformation, the query can use an XML index.

Parent topic: XML data indexing

Related concepts

XMLEXISTS predicate for querying XML data

Related reference

CREATE INDEX statement