[Exist-open] 504 error in relatively small query

[Ralph C. <ra...@ra...>]

Hi all, I was going to post this in an xQuery forum, but at small 
numbers this query works fine and I feel confident that the issue here 
is in my exist-db config.

I'm trying to return orphaned <ref> elements from a recent update that 
was set up wrong. I'm using the following query to get the results:

> for $ref in 
> subsequence(collection('/db/apps/****/data')//ref[@type='2'],1,####)
> 
> where 
> not(exists(doc('/db/apps/****/data/listPerson.xml')//person[@xml:id=$ref/@target]))
> 
> return
> $ref

This returns absolutely fine up to ~1200 items in the subsequence $ref 
but by the time we get closer to 2000 (and more) this returns a 504 
gateway time-out error in roughly 60s. This does not seem to me to be a 
significantly onerous task (especially considering other things that are 
handled well).

I've tried

declare option exist:timeout "600000" (which should be ten minutes)

to extend the timeout, but I'm getting the same error after ~60s.

Any ideas, as the total I'm trying to get to is ~12000 records of which 
I have no idea how many are orphaned....

Cheers

Ralph