Comments inline:
On 22/01/2020, 10:27, "Élie Roux" <[email protected]> wrote:
Thanks a lot, after some investigation, here are a few results:
- the problem was that I had no .opt file and that the default
behavior was fixed.opt (or so it seems), when adding a none.opt (or a
stats.opt) the performance went from 1200 to 250ms (with the version
with the big filter version)
- the version with VALUES went down to 150ms using none.opt or
stats.opt, that's really cool
- the version with a big filter went down to 150ms when I turn off
optimizations (the big union takes more time than a simple filter)
I'll open the following JIRA issues:
* documenting that fixed.opt is the default when there is no file
* documenting that --tdb should be preferred over --loc in most cases
in tdbquery
These you can do yourselves, find the relevant part of the website and hit the
Improve this Page button at the top and follow the instructions
* feature request: ability to turn off some (or all) optimizations
for a query, a bit like
https://wiki.blazegraph.com/wiki/index.php/QueryHints
This already exists and is done by setting context symbols to true/false as
desired for a given optimisation (I think for CLI its something like --set
<symbol>=false to disable a given optimisation. However I don't think this is
well documented, you can find the symbols values in the source code -
https://github.com/apache/jena/blob/92788c44255569a7c62d915b1e59a7d340917065/jena-arq/src/main/java/org/apache/jena/query/ARQ.java#L323
So for example you might do --set arq:optFilterPlacement=false
Rob
I'm satisfied with the current state.
Best,
--
Elie
