Hi,
I have a specific piece of code which fails to run as expected. Unfortunately i didn't manage to create an MCVE so far. The part of code that should fail in my script is:
some $i in $data satisfies starts-with($i, $string)
Where $data is a list of strings, and $string is a sequence of two strings - example ("S1", "S2"). The Query executes without error, but the trace message is never visible. The part of the Query plan that executes successfully (while it shouldn't) is:
<StaticFunc name="common:startsWith" type="xs:boolean" arg0="elements" arg1="string"> <GFLWOR type="xs:boolean" size="1"> <Let type="xs:string*"> <Var name="$string" id="178" type="xs:string*"/> <FnTrace name="trace(value[,label])" type="xs:string*"> <StaticFuncCall name="common:string" tailCall="false" type="xs:string*"> <VarRef> <Var name="$string" id="177" type="item()*" promote="true"/> </VarRef> </StaticFuncCall> <Str type="xs:string">STRING: </Str> </FnTrace> </Let> <Quantifier option="some" type="xs:boolean" size="1"> <GFLWOR type="xs:boolean*"> <For type="xs:string" size="1"> <Var name="$i" id="180" type="xs:string"/> <StaticFuncCall name="common:string" tailCall="false" type="xs:string*"> <VarRef> <Var name="$elements" id="176" type="item()*" promote="true"/> </VarRef> </StaticFuncCall> </For> <FnTrace name="trace(value[,label])" type="xs:boolean" size="1"> <FnStartsWith name="starts-with(string,sub[,collation])" type="xs:boolean" size="1"> <VarRef type="xs:string" size="1"> <Var name="$i" id="180" type="xs:string"/> </VarRef> <VarRef type="xs:string*"> <Var name="$string" id="178" type="xs:string*"/> </VarRef> </FnStartsWith> <Str type="xs:string">SATISFY: </Str> </FnTrace> </GFLWOR> </Quantifier> </GFLWOR> </StaticFunc>
I'm not sure if you can find anything from the Query plan for why this is happening. This fails either with or without inlining. Regards,
George
I'm not sure if you can find anything from the Query plan for why this is happening. This fails either with or without inlining. Regards,
Difficult to tell without investing some considerable time I guess… How does the original query look like that produces this query plan? Maybe we still have a chance to get this reproducible?
Hi Christian,
On 2/13/19 6:19 PM, Christian Grün wrote:
Difficult to tell without investing some considerable time I guess… How does the original query look like that produces this query plan? Maybe we still have a chance to get this reproducible?
There are just two function involved in this.
declare function common:string($elements) as xs:string* { let $values := data($elements) let $values := for $i in $values return lower-case(normalize-space(string($i))) return $values };
declare function common:startsWith($elements, $string) as xs:boolean { let $string := common:string($string) => trace("STRING: ") let $data := common:string($elements) return some $i in $data satisfies starts-with($i, $string) => trace("SATISFY: ") };
The main query is 5823 lines so it's not very easy to find out what's going on. My assumption is that for some reason the Quantifier expressions get optimized to ignore errors. What I noticed is that if I change the following:
satisfies starts-with($i, $string) to satisfies 1 = "a"
It will finally fail as expected, even with the optimized final query plan.I will keep trying to create a reproducible example. The alternative is to send you the main query along with the source XML file. Best,
George
This doesn’t really contribute to your problem, but if all items in $elements are of type node() or xs:string, you could possibly simplify your query to something as follows:
declare function common:string($elements) as xs:string* { $elements ! lower-case(normalize-space(.)) };
If you won’t, BaseX will probably do it for you, so… Never mind
In general, if trace() yields no results, I would assume that your corresponding code snippet is never executed.
On Wed, Feb 13, 2019 at 5:30 PM George Sofianos gsf.greece@gmail.com wrote:
Hi Christian,
On 2/13/19 6:19 PM, Christian Grün wrote:
Difficult to tell without investing some considerable time I guess… How does the original query look like that produces this query plan? Maybe we still have a chance to get this reproducible?
There are just two function involved in this.
declare function common:string($elements) as xs:string* { let $values := data($elements) let $values := for $i in $values return lower-case(normalize-space(string($i))) return $values };
declare function common:startsWith($elements, $string) as xs:boolean { let $string := common:string($string) => trace("STRING: ") let $data := common:string($elements) return some $i in $data satisfies starts-with($i, $string) => trace("SATISFY: ") };
The main query is 5823 lines so it's not very easy to find out what's going on. My assumption is that for some reason the Quantifier expressions get optimized to ignore errors. What I noticed is that if I change the following:
satisfies starts-with($i, $string) to satisfies 1 = "a"
It will finally fail as expected, even with the optimized final query plan. I will keep trying to create a reproducible example. The alternative is to send you the main query along with the source XML file. Best,
George
Hi again,
My mistake, I failed to see an error in my code which returned empty elements, which resulted in the quantifier not executing. Sorry for wasting your time and have a good evening!
On 2/13/19 6:19 PM, Christian Grün wrote:
I'm not sure if you can find anything from the Query plan for why this is happening. This fails either with or without inlining. Regards,
Difficult to tell without investing some considerable time I guess… How does the original query look like that produces this query plan? Maybe we still have a chance to get this reproducible?
basex-talk@mailman.uni-konstanz.de
-
Christian Grün -
George Sofianos