Hi, Nice work. I wonder if the BaseX query optimizer could not spot the idioms for the set operations and rewrite the query to something similar for the cases:
distinct-values(($arg1, $arg2)) distinct-values($arg1[.=$arg2]) distinct-values($arg1[not(.=$arg2)]) >From : http://www.xqueryfunctions.com/xq/c0015.html#c0075 Regards /Andy On Wed, Sep 25, 2013 at 8:04 PM, Arve Gengelbach <a...@basex.org> wrote: > Hej Arto, > > One can even improve your map2 by using the [Simple map operator]. > > declare function local:difference-map-2-excl($a, $b) { > let $m2 := map:new($b ! map:entry(., true())) > return $a ! (if($m2(.)) then () else .) > }; > > - map 299.47 ms > - map2 290.96 ms > - map2 + ! 128.25 ms > > cheers > Arve > > [Simple map operator] http://www.w3.org/TR/xquery-30/#id-map-operator > > Am 25.09.13 10:41 schrieb Arto Viitanen: >> >> >> -----Original Message----- >> From: Arve Gengelbach [mailto:a...@basex.org] >> Sent: 25. syyskuuta 2013 9:08 >> To: Arto Viitanen >> Cc: basex-talk@mailman.uni-konstanz.de >> Subject: Re: [basex-talk] Set Operator Examples >> >> Hej Arto, >> >> just being interested: >> How does it compare to a FLOWR expression? >> >> declare function local:difference-flowr($a, $b) { >> for $x in $a >> where not($x = $b) >> group by $x >> return $x[1] >> }; >> >> pred 51787.06 ms >> map 485.16 ms >> map2 325.09 ms >> flowr 45275.97 ms >> >> -- >> Arto Viitanen >> Finland >> > _______________________________________________ > BaseX-Talk mailing list > BaseX-Talk@mailman.uni-konstanz.de > https://mailman.uni-konstanz.de/mailman/listinfo/basex-talk _______________________________________________ BaseX-Talk mailing list BaseX-Talk@mailman.uni-konstanz.de https://mailman.uni-konstanz.de/mailman/listinfo/basex-talk
