Hello,
I'm experiencing some strange behavior when executing the following query in
the BaseX 9.2.4 GUI (nevermind the awkward query structure - that is just to be
able to inspect the results of the individual evaluation steps):
let $t := <x>200.0000</x>
let $num := number($t)
let $gt5000 := $num gt 5000
let $ltMinus5000 := $num lt -5000
return $gt5000 or $ltMinus5000
The result is true, although it should be false.
The compilation and optimization logs for this query in the GUI tell us the
following:
----------
Compiling:
- rewrite > comparison to range comparison: ($num_1 > 5000) -> ($num_1 >=
5000.000000000001)
- rewrite 'gt' comparison to range comparison: ($num_1 gt 5000) -> ($num_1 >=
5000.000000000001)
- pre-evaluate unary expression to xs:integer item: -5000
- rewrite < comparison to range comparison: ($num_1 < -5000) -> ($num_1 <=
-5000.000000000001)
- rewrite 'lt' comparison to range comparison: ($num_1 lt -5000) -> ($num_1 <=
-5000.000000000001)
- inline $gt5000_2
- inline $ltMinus5000_3
- simplify or: (true())
- pre-evaluate or to xs:boolean item: (true()) -> true()
- remove unused variable $num_1
- remove unused variable $t_0
- simplify FLWOR expression: true()
Optimized Query:
true()
----------
When the return statement is changed to "return
($num,$gt5000,$ltMinus5000,$gt5000 or $ltMinus5000)" then the result of the
boolean operation (last element of the result sequence) is false, as expected.
The GUI log then is:
----------
Compiling:
- rewrite > comparison to range comparison: ($num_1 > 5000) -> ($num_1 >=
5000.000000000001)
- rewrite 'gt' comparison to range comparison: ($num_1 gt 5000) -> ($num_1 >=
5000.000000000001)
- pre-evaluate unary expression to xs:integer item: -5000
- rewrite < comparison to range comparison: ($num_1 < -5000) -> ($num_1 <=
-5000.000000000001)
- rewrite 'lt' comparison to range comparison: ($num_1 lt -5000) -> ($num_1 <=
-5000.000000000001)
Optimized Query:
let $t_0 := element x { ("200.0000") } let $num_1 := number($t_0) let $gt5000_2
:= ($num_1 >= 5000.000000000001) let $ltMinus5000_3 := ($num_1 <=
-5000.000000000001) return ($num_1, $gt5000_2, $ltMinus5000_3, ($gt5000_2 or
$ltMinus5000_3))
----------
Am I missing something, or could this be a bug in BaseX 9.2.4? With BaseX
9.0.2, both queries (with the different return statements) returned the
expected value false for the boolean operation.
Best regards,
Johannes
