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.com> wrote:

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

--
Regards

Shanshan

School of Computing

National University of Singapore