Question: What do you mean by value index?
Answer: A "value" or "range" index supports standard comparisons with =, >, < and the like. In short, the structural index helps with the expression
collection("/db")/doc/attribute/rut_afiliado
but you will also need a range index to speed up the value lookup on rut_afiliado:
Question: I am doing a performance test of query operation in eXist，and the result following showed time consumption for query about 10 records increases when the total number of all records stored in database increases. There is no indexes.
Answer: Without an index, if your query involves a comparison, eXist has to do a full scan over all the relevant nodes in the database. The more data is in the db, the more nodes have to be scanned.
Question: When I insert a collection with new XML documents, the total size of files stored at "eXist.webapp.WEB-INF.data" increases (obviously). But, when I delete a collection or a set of collection the size of the same files does not decrease?? Why this happens?
Answer: The size of the .dbx files will never decrease. If you delete a document or collection, the pages used by that resource will be freed or rather: marked as deleted. They will be reused for the next document or collection you store. Maybe it is easier to understand if you view the .dbx files as "partitions" rather than "files". The db files will never shrink, though they can be empty.
Question: I am in the process of documenting the checkout and build using eclipse. Once the code is checked out and I switch to the Java perspective, I get the missing jar errors.
Answer: The missing jars are used by extension modules which are not build by default. You can simply ignore those messages as long as you are not using or editing the corresponding extensions.
To enable the extensions, edit extensions/indexes/build.properties. Calling build.sh the next time will download the missing jars.