10. The method of claim 1 , wherein: a first subset of said plurality of resources are stored in an object-relational (O-R) format, a second subset of said plurality of resources are stored in a large object (LOB) format, and the index includes a locator column that is used as both a locator of resources stored in the O-R format and a locator of resources stored in the LOB format.
10. The method of claim 1 , wherein: a first subset of said plurality of resources are stored in an object-relational (O-R) format, a second subset of said plurality of resources are stored in a large object (LOB) format, and the index includes a locator column that is used as both a locator of resources stored in the O-R format and a locator of resources stored in the LOB format. 12. The method of claim 10 , wherein: the query specifies an XPath string that indicates a fragment is to be extracted; the fragment is a portion of a particular resource of said plurality of resources; the particular resource is an XML document conforming to an XML schema; the index is used to determine a locator value, corresponding to the locator column, of one or more nodes specified by the XPath string; and the locator value is used to extract the fragment from where the particular resource is stored.