Hi Vishnu,
It would help if you could explain why you need that list. But in general
the best option would be to pre-calculate the list I guess. You can save it
as a server-field (xdmp:set-server-field), to keep the list in memory on
each host. But you would need an algorithm to initialize it, and each doc
commit would have to check and update that list. The latter can be done
with a post-commit trigger. The first can be done best by the strategy I
already mentioned: divide all docs in chunks of 100 to 1000 docs, calculate
distinct names of each chunk, and merge that somehow to the final list.
You could also raise the tree size setting temporarily to do that initial
calculation..
Kind regards,
Geert
*Van:* general-boun...@developer.marklogic.com [mailto:
general-boun...@developer.marklogic.com] *Namens *VISH RAJPUT
*Verzonden:* maandag 26 maart 2012 14:29
*Aan:* MarkLogic Developer Discussion
*Onderwerp:* Re: [MarkLogic Dev General] Fwd: [1.0-ml]
XDMP-EXPNTREECACHEFULL
Thanks Geert,
Is there any alternate solution to find the unique elements within a
database?
Warm Regards,
Vishnu
On Mon, Mar 26, 2012 at 5:55 PM, Geert Josten <geert.jos...@dayon.nl> wrote:
Hi Vishnu,
90 mb isn’t much indeed, but MarkLogic is configured to keep a low memory
footprint, even if there are 30 concurrent requests. To make that sure, the
tree size limit (look at the database setting in the admin interface) is
usually pretty low. I have 8Gb and still it is set to no more than 85mb by
default. But you can increase it if you like.
A more streaming approach like my advice attempts to achieve to some extend
helps keeping the footprint low, and keep MarkLogic fast.
Kind regards,
Geert
*Van:* general-boun...@developer.marklogic.com [mailto:
general-boun...@developer.marklogic.com] *Namens *VISH RAJPUT
*Verzonden:* maandag 26 maart 2012 14:17
*Aan:* MarkLogic Developer Discussion
*Onderwerp:* Re: [MarkLogic Dev General] Fwd: [1.0-ml]
XDMP-EXPNTREECACHEFULL
Thanks Geert,
But still it shows *XDMP-EXPNTREECACHEFULL:
distinct-values(collection("ContentAnalysis")//*/local-name()) --
Expanded tree cache full on host.... *the database overall size is only
90MB i don't think it is so huge data for marklogic....
Regards,
Vishnu
On Mon, Mar 26, 2012 at 1:25 PM, Geert Josten <geert.jos...@dayon.nl> wrote:
Hi Vishnu,
Your FLWOR expression won’t return distinct names, since you are applying
the function to each individual name. You should write:
distinct-values(
for $a in //*
return $a
)
Or better:
distinct-values(collection()//*/local-name())
But this still might not perform well, or still max out on list or tree
caches. This approach is creating a complete list of all element names
first, and starts applying distinct-values only thereafter. You might
consider taking multiple steps, like per doc first, and then clustering per
100 files, and only then all clusters. You could also just take 100 random
samples, and use that. That doesn’t guarantee a 100% complete list, but it
remains performant even if your database grows 10 or 100 fold.
Kind regards,
Geert
*Van:* general-boun...@developer.marklogic.com [mailto:
general-boun...@developer.marklogic.com] *Namens *VISH RAJPUT
*Verzonden:* maandag 26 maart 2012 8:29
*Aan:* general@developer.marklogic.com
*Onderwerp:* [MarkLogic Dev General] Fwd: [1.0-ml] XDMP-EXPNTREECACHEFULL
The size of the all files is 90 MB approx.
---------- Forwarded message ----------
From: *VISH RAJPUT* <svishnu.sin...@gmail.com>
Date: Mon, Mar 26, 2012 at 11:56 AM
Subject: [1.0-ml] XDMP-EXPNTREECACHEFULL
To: general@developer.marklogic.com
Hi,
I have 2000 files in Marklogic database within a single forest and i want
to find out the unique element name from this database for the whole 2000
files. For this i wrote the below query:-
for $a in //*
return distinct-values($a/local-name()))
but by this i got an error "*[1.0-ml] XDMP-EXPNTREECACHEFULL" * what should
i do?
Regards,
Vishnu Singh
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