[xquery-talk] Xquery update performance question

[Sava Jurisic]

Hi All,

this is my first post to this group!

I am using eXist DB and I am stuck with the performance of the following query. 
It took 12hours to complete???

Here is the scope:

We have many collections within a collection, something like this:

/db/patients/1/patient.xml
/db/patients/2/patient.xml
... etc up to 4000+ subcollections (but less than 10,000) 
/db/patients/4003/patient.xml

Now I want to run a query to update some values within all patient.xml 
documents, the query looks something like this:

for $p in collection("/db/patients")/p[abc eq "" and def ne ""] return (update 
value $p/abc with "test1", update value $p/def with "", update value $p/ghi with 
"test2") 

(: etc, up to 4-5 elements to be updated :)

Problem: When I ran this query, it took about 12 hours to finish. Did I do 
something wrong here?

PS: If the "update..." portion above is replaced with "return $p", the query ran 
very fast, about less than 1 minute; so it looks like the update part is slowing 
down.. but why?

Many thanks,
Sava