XML index ANDing and ORing access requests

The XANDOR access request element can be used to specify that the optimizer is to use multiple XANDORed index over XML data scans to access a local table. It is defined by the complex type XANDORType.

XML Schema

   <xs:complexType name="XANDORType">
      <xs:complexContent>
         <xs:extension base="accessType"/>
      </xs:complexContent>
   </xs:complexType>

Description

The complex type XANDORType is a simple extension of the abstract type accessType. No new elements or attributes are added.

Example

Given the following query:

SELECT * FROM security
  WHERE trans_date = CURRENT DATE AND
    XMLEXISTS('$SDOC/Security/SecurityInformation/
      StockInformation[Industry = "Software"]') AND
    XMLEXISTS('$SDOC/Security/Symbol[.="IBM"]')

The following XANDOR guideline specifies that the SECURITY table should be accessed using a XANDOR operation against all applicable XML indexes. Any relational indexes on the SECURITY table will not be considered, because a relational index cannot be used with a XANDOR operator.

<OPTGUIDELINES>
  <XANDOR TABLE='SECURITY'/>
</OPTGUIDELINES>