Hi Christian,
Thanks for your reply.
First, I am a layman of XML DB, do not have much experience of it. I am just very curious why for read-only queries, they will compete for disk I/O. As in relational database management systems, we may control the granularity of lock. Is it possible to allow multiple read thread on the same I/O, for read only queries.
It there anyway we can brutely load the whole index and then do the queries.
Thanks,
On Mon, Mar 24, 2014 at 5:06 PM, Christian Grün christian.gruen@gmail.comwrote:
Hi Ying,
e.g. the dataset I use is DBLP, one of the example query is
for $x in db:open('dblp_2013')/dblp/article[child::pages and
child::title]
let $y := count($x/author) return concat($y, "/t", db:node-id($x))
Yes, I agree there is not much that can be done to speed up this query.
It is true that these queries are competing for the same resource. So you mean that each query causes a lot of disk I/O?
Exactly. All DBLP articles need to be parsed by this query, and > 1 million result strings will be generated, resulting in a query time of appr. 0.005 ms per result.
Hope this helps, Christian
However all these queries are read-only. It there any room to improve
this?
-- Regards
Shanshan
School of Computing National University of Singapore