Like Damon, I suspect that the /item... bit is the expensive part, probably
because of the database lookup inside the predicate.
But why use search:search() at all? It seems to me that you aren't really using
any of the search:search features, and would be better off using cts:query
directly.
for $n in cts:search(
doc(),
cts:and-query(
(cts:element-attribute-range-query(
xs:QName("journal_cite"),
xs:QName("datetimeRecevied"), ">", $dateTime),
cts:collection-query('/citation/type/journal_cite'))))[1 to 100]
let $doi := $n/citation/target_doi/data(.)
return element result {
$n,
/item[@doi = $doi] }
If you only wanted the URIs you could also use cts:uris() - but since you are
fetching the documents anyway, cts:search is probably a little more efficient.
-- Mike
On 21 Mar 2012, at 06:02 , Damon Feldman wrote:
> Dean,
>
>
> Try removing sub-expressions until you have a minimal expression that shows
> the problem. E.g. does just the search:search() call work, without any other
> code?
>
> I suspect your XPath: /item[@doi= <expr>] may be the problem. If the <expr>
> is not properly formed (e.g. missing a namespace, misspelled element) you
> could get many items retrieved rather than just one, and that would be
> executed for every result.
>
> Retrieving all results is not possible with search:search() to avoid huge
> queries, which would time out. If your DB only has, say, 10,000 items and you
> think they can come back in a single call, set the page size to 10,000. If
> you think you can get 20MM in one shot, use that limit, etc. The idea is to
> force the developer to think hard about how big that result set can be and
> explicitly set the limits.
>
> Yours,
> Damon
>
> From: [email protected]
> [mailto:[email protected]] On Behalf Of Dean Pullen
> Sent: Wednesday, March 21, 2012 7:37 AM
> To: [email protected]
> Subject: [MarkLogic Dev General] Query times out, and page-limit constraints
>
> Hi all,
>
> I'm relatively new to Marklogic and have an example query to debug (at end of
> email).
>
> I've got two questions -
> 1) Why does this time out? We have a lot of data, but it's constrained by a
> page-limit of 100 and by the given $dateTimeStr variable. Should I be
> searching using some other method, like a constraint or what? You'll notice
> the search:search first parm is '' i.e. blank.
>
> 2) How can I (once question 1 is 'fixed') retrieve ALL results and not just
> the number of pages specified by the page-limit.
>
>
> Many thanks,
>
> Dean.
>
>
> QUERY:
>
>
> xquery version "1.0-ml";
>
> import module namespace search = "http://marklogic.com/appservices/search";
> at "/MarkLogic/appservices/search/search.xqy";
>
> declare variable $dateTimeStr as xs:string := '2012-02-01T18:43:30.728';
>
>
> Ddeclare function local:retrieveiteminfo($result as element(citation)) as
> element(search:result) {
>
> <search:result>
> {/item[@doi = $result/target_doi]}
> </search:result>
> };
>
> let $dateTime := xs:dateTime($dateTimeStr)
>
> let $top-citation-results:= search:search('',
> <options xmlns="http://marklogic.com/appservices/search";>
> <additional-query>{
> cts:and-query((
> cts:element-attribute-range-query(xs:QName("journal_cite"),
> xs:QName("datetimeRecevied"), ">", $dateTime),
> cts:collection-query('/citation/type/journal_cite')
> ))
>
> }
> </additional-query>
> </options>,
> 1,
> 100
> )
>
>
> for $uri in $top-citation-results/search:result/@uri
> return
> <search:result>{fn:doc($uri)}{/item[@doi =
> fn:doc($uri)/citation/target_doi]}</search:result>
>
>
>
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