On Jul 23, 2010, at 11:43 AM, Liz Glasser wrote: > I have a ton of records in my xindice database that look like: > <MyRootElement myId="...">.....</MyRootElement> > > I need the most efficient way to get a list of all values for myId. How can I > best do this? > > Basically if this was a relational database and I had a table called > MyRootElement, I'd do "select myId from MyRootElement". I need a xindice > equivalent.
Hey Liz, The query you are looking for is "/MyRootElement/@myId". Using command line you can query it like this (replace /db/my/collection with path to your collection): xindice xpath -c /db/my/collection -q /MyRootElement/@myId Results should look like: <xq:result xmlns:xq="http://xml.apache.org/xindice/Query"; myId="value" xq:col="/db/my/collection" xq:key="MyDocument1" /> ... Now, if only some % of documents in this collection contain this root element/attribute, then you can speed that query up by build an index on the element/attribute pair. Index will allow query engine to skip documents which do not have that element/attribute pair. Index also helps if you want to find a document by value of the myId attribute. Command to build the index looks like: xindice add_indexer -c /db/my/collection -n MyRootElementMyId -p MyRootElement@ myId OTOH, if all documents have the same structure, then in order to extract all of the values, query engine will have to iterate through all of the documents in the collection - and index will be of no help. Hope that helps. Vadim
