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From: "Jonathan Rochkind" <[log in to unmask]> > Another question though. I note when looking up schemaInfo... I'm a bit > confused by the "sort" attribute. How could you sort by a schema? What is > this attribute actually for? Well indulge me, this is best explained by the current OASIS SRU draft. (The current and earlier specs don't do a good job here. But for background if interested: sorting as an SRU function was supported in SRU 1.1 and taken out of version 1.2, replaced by sorting as a function of the query language rather than the protocol. For the OASIS work it's in both. For the current spec at LC, which reflects 1.2, the attribute doesn't even make sense. If you go back to the 1.1 archive it does. Still, the OASIS document treats it more clearly.) See http://www.loc.gov/standards/sru/oasis/sru-2-0-draft-most-current.doc See section 9.1. So essentially, when you sort in SRU, you provide an XPath expression. The XPath expression is meaningful in the context of a schema, but the *record schema* may not be the most meaningful schema for purposes of sorting, there may be another schema more meaningful. So, you have the capability to specify not only a record schema but an auxiliary sort schema. A given schema that an Explain file lists will usually be one that is used as a record schema, but it may also be usable as a sort schema. That's what the sort attribute tells you. --Ray