Bugs item #2144639, was opened at 2008-10-03 18:25
Message generated for change (Comment added) made by stmane
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Category: PF general
Group: Pathfinder 0.24
Status: Open
Resolution: None
Priority: 5
Private: No
Submitted By: Loredana Afanasiev (lafanasi)
Assigned to: Lefteris Sidirourgos (lsidir)
Summary: XQ: fn:collection() in algebra version
Initial Comment:
Hi Lefteris,
as discussed on Thu, I add this as a bug, so that you can close it soon :)
[EMAIL PROTECTED] xq]$ mclient -lx -s 'fn:collection("MotiesTweedeKamer")'
MAPI = [EMAIL PROTECTED]:50000
QUERY = fn:collection("MotiesTweedeKamer")
ERROR = !fatal error: Algebra implementation for function `fn:collection'
unknown.
Thanks,
l.
----------------------------------------------------------------------
>Comment By: Stefan Manegold (stmane)
Date: 2008-10-08 15:31
Message:
Loredana,
(1)
The performance differences you experience are most probably not caused by
fn:collection() vs. pf:collection() but by ALG vs. MPS (see also (2)) ---
just try MPS with pf:collection() and it should show the same performance
as MPS with fn:collection().
(2)
Since MPS and ALG use quite different ways & techniques to translate and
optimize queries, it is expected that they show performance differences
(sometimes severe ones) on the same query; we (plus the Pathfinder folks in
Tbingen) have to check, what goes wrong with ALG in case of your query
...
Thanks for reporting it.
(3)
We also have to check the unexpected(?) behaviour of pf:collection().
Thanks for reporting it.
----------------------------------------------------------------------
Comment By: Loredana Afanasiev (lafanasi)
Date: 2008-10-08 15:13
Message:
Subject: fn:collection() vs pf:collection()
Hi Lefteris and all,
I think this relevant to this bug report.
I get huge performance times difference when switching from
fn:collection() to pf:collection(). I can you please advise me how to avoid
the long times while running on algebra version?
thanks in advance,
l.
[EMAIL PROTECTED] xq]$ more q9-fn.xq
let $col := fn:collection("MotiesTweedeKamer")
for $y in distinct-values(for $y in $col//hiddendatum
return substring-before(fn:str
ing($y),'.'))
let $thisyear := $col//document
[substring-before(fn:string(.//hiddendatum[1]),'.')=$y]
let $partij := distinct-values($thisyear//partij)
for $p in $partij
let $aantalingediendemoties :=
count($thisyear[.//indienergnlod//partij=$p])
let $aantalmedeingediendemoties :=
count($thisyear[.//medeindienergnlod//partij=$p])
order by $y descending,
$aantalingediendemoties descending,
$aantalmedeingediendemoties descending
return
<aantal jaar='{$y}'
partij='{$p}'
aantalingediendemoties='{$aantalingediendemoties}'
aantalmedeingediendemoties='{$aantalmedeingediendemoties}'
/>
[EMAIL PROTECTED] xq]$ mclient -lx -g -t q9-fn.xq
Trans 35.174 msec
Shred 0.000 msec
Query 4401.659 msec
Print 2.680 msec
Timer 4487.610 msec
[EMAIL PROTECTED] xq]$ more q9-pf.xq
let $col := pf:collection("MotiesTweedeKamer")
for $y in distinct-values(for $y in $col//hiddendatum
return substring-before(fn:str
ing($y),'.'))
let $thisyear := $col//document
[substring-before(fn:string(.//hiddendatum[1]),'.')=$y]
let $partij := distinct-values($thisyear//partij)
for $p in $partij
let $aantalingediendemoties :=
count($thisyear[.//indienergnlod//partij=$p])
let $aantalmedeingediendemoties :=
count($thisyear[.//medeindienergnlod//partij=$p])
order by $y descending,
$aantalingediendemoties descending,
$aantalmedeingediendemoties descending
return
<aantal jaar='{$y}'
partij='{$p}'
aantalingediendemoties='{$aantalingediendemoties}'
aantalmedeingediendemoties='{$aantalmedeingediendemoties}'
/>
[EMAIL PROTECTED] xq]$ mclient -lx -t q9-pf.xq
Timer 584185.070 msec
[EMAIL PROTECTED] xq]$ diff q9-fn.xq q9-pf.xq
1c1
< let $col := fn:collection("MotiesTweedeKamer")
---
> let $col := pf:collection("MotiesTweedeKamer")
Besides this there is something strange happening with pf:collection().
The website says:
"
pf:collection() returns a single special collection node, whose immediate
children are the document nodes. Therefore, fn:collection("my-collection")
is roughly equivalent to pf:collection("my-collection")/*.
"
While I get:
[EMAIL PROTECTED] xq]$ mclient -lx -g -s
'count(fn:collection("MotiesTweedeKamer"))'
27946
[EMAIL PROTECTED] xq]$ mclient -lx -g -s
'count(pf:collection("MotiesTweedeKamer"))'
1
[EMAIL PROTECTED] xq]$ mclient -lx -g -s
'count(pf:collection("MotiesTweedeKamer")/*)'
0
[EMAIL PROTECTED] xq]$ mclient -lx -s
'count(pf:collection("MotiesTweedeKamer")/*)'
0
[EMAIL PROTECTED] xq]$ mclient -lx -s
'count(pf:collection("MotiesTweedeKamer")/*/*)'
0
[EMAIL PROTECTED] xq]$ mclient -lx -s
'count(pf:collection("MotiesTweedeKamer")/*/document)'
0
[EMAIL PROTECTED] xq]$ mclient -lx -s
'count(pf:collection("MotiesTweedeKamer")//document)'
27946
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