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Message-ID: <4B4264D0.5060009@yahoo.com>
Date: Mon, 04 Jan 2010 13:59:44 -0800
From: Vinayak Borkar <vborky@yahoo.com>
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To: vxquery-dev@incubator.apache.org
Subject: Re: XTest
References: <4B424D00.6050200@yahoo.com> <4B425478.3000000@yahoo.com>
 <e75283b11001041324l695be737i341e2c2f52d49e0d@mail.gmail.com>
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Jochen,

The test I mention is not something we have come up with. XQTS is the 
official testsuite to test XQuery compliance, and the query I mention is 
one out of that suite.

The fact that this query takes a long time means that we need to fix the 
engine to make this case more efficient.

If you are interested I could describe in more detail the exact issue 
and some possible fixes.

Vinayak

Jochen Wiedmann wrote:
> Consider to enable the test only if some system property is set. A
> normal user won't be able to distinguish between "infinite loop" and
> "tales a very very long time".
> 
> Alternatively, select a representative subset of the 1.1M integers and
> restrict the test to those.
> 
> Jochen
> 
> 
> On Mon, Jan 4, 2010 at 9:50 PM, Vinayak Borkar <vborky@yahoo.com> wrote:
>> Its not an infinite loop --
>> Expressions/Construct/DirectConElem/DirectConElemContent//Constr-cont-document-3.xq
>>
>> is taking a long time to run. I am pasting the query below.
>>
>> The query iterates over about 1.1 M integers 70 at a time and calls
>> subsequence() for the 70 items in the window. This is a quadratic operation
>> in the engine -- and takes a long time.
>>
>> Should we optimize this case?
>>
>>
>> Thanks,
>> Vinayak
>>
>>
>> --- Query begin ---
>>
>>
>> declare variable $codepoints as xs:integer+ := (9, (: 0x9 :)
>>                                                10,(: 0xA :)
>>                                                13,(: 0xD :)
>>                                                32 to 55295, (: 0x20 - 0xD7FF
>> :)
>>                                                57344 to 65532, (: 0xE000 -
>> 0xFFFD :)
>>                                                65536 to 1114111 (: 0x10000 -
>> 0x10FFFF :));
>> declare variable $count as xs:integer := count($codepoints);
>> declare variable $lineWidth as xs:integer := 70;
>>
>> <allCodepoints>
>>    <!-- Each <r>-element represents a codepoint range. The 's' attribute
>>         is the start codepoint, the 'e' attribute is the end codepoint.
>>         Note that these are only *Hints*, since the character range is not
>> contiguous.
>>      -->
>> {
>>    "&#xA;",
>>    "&#xA;",
>>    (: The outputted file is rather big, so to make it managable, we output
>>       a chunk of $lineWidth characters in each element.
>>     :)
>>    for $i in (1 to $count idiv $lineWidth)
>>    let $startOffset := (($i - 1) * $lineWidth) + 1
>>    return (<r s="{$codepoints[$startOffset]}"
>>               e="{$codepoints[$startOffset] + $lineWidth}">
>>                {
>>                        codepoints-to-string(subsequence($codepoints,
>> $startOffset, $lineWidth))
>>                }
>>           </r>, "&#xA;")
>> }
>> </allCodepoints>
>>
>> --- Query end ---
>>
>> Vinayak Borkar wrote:
>>> Till,
>>>
>>>
>>> Does XTest on the test suite terminate? Some query is throwing the engine
>>> into an infinite loop. Do you see this?
>>>
>>>
>>> Thanks,
>>> Vinayak
>>>
>>
> 
> 
>