On 25/11/13 14:23, Rob Vesse wrote:
Maria
Yes you can do this, in ARQ the iterator which backs the ResultSet or
Iterator<Triple> returned from the appropriate QueryExecution.execX()
calls represents the plan and iterating over it causes the actual
execution to occur and is thus the execution time I.e.
// Assume we have a query and a dataset ready to go
QueryExecution qe = QueryExecutionFactory.create(query, dataset);
// Starting to execute the query only actually triggers plan calculation
// Time around this to get the plan compilation time
ResultSet results = qe.execSelect();
// Iterating the results actually executes the query
// Time around the while loop to get execution time
while (results.hasNext() {
results.next();
}
That's the best there is. It's not as clear cut as completely separate
plan and execute stages. Only the high-level optimizations are
measurable - TDB specific low level optimizations happen during execution.
The major cost for TDB is whether the file caches are hot or cold.
Andy
Rob
p.s. Please DO NOT email/CC developers with your question as well as
posting to the list or re-post your question multiple times, developers
are all volunteers and will answer your questions as and when they have
the spare time. Also as Andy points out people are in potentially vastly
difference timezones to you so you should always allow at least 24 hours
for a response if not longer.
Emailing people directly as well as the list or multiple posting only
serves to annoy people and actually reduces the chance that people will
respond to your questions. It also subverts the purpose of the list which
is to allow any knowledgeable user the chance to respond and share their
knowledge with the wider community.
On 25/11/2013 08:08, "Maria Jackson" <[email protected]> wrote:
I need to know these query times as I am benchmarking Jena TDB against
postgreSQL. With postgresql I am able to separately retrieve the query
execution time after the plan has been generated by postgresql using
\timing. It would be great if Jena could also give me the time it takes
to
retrieve the results after the plan has been generated separately by Jena
as that would help me take a one to one comparison.
I'll be really greatful to you for the guidance.
On Mon, Nov 25, 2013 at 5:48 AM, Maria Jackson
<[email protected]>wrote:
One can find time of query execution in Jena from tdbquery using --time.
But does this --time include the plan generation time. If yes, is it
possible to find:
(plan generation time) and (time to retrieve the results after the plan
has been generated separately in Jena)?
