Hi everyone! it's me again. 

Here is my doubt:

If I execute this query:

             (# db:enforceindex #) {                  
                  for $db in ('US00','US01','US02')
                  for $tmUS in db:open($db)/trademark-applications-daily/application-information/file-segments/action-keys/case-file
                  where $tmUS/case-file-header/mark-identification/text() contains text { 'apple' }
                  return $tmUS/case-file-header/mark-identification/text()
                }

I get 4k results in 139ms from three databases of 90GB and 13M of records. It works like a charm. [01]

But, if I include that query into a for and then into a switch ( I tried with if-then-else too ), the same query returns only 11 results in 107ms [02]:

declare namespace gb="http://www.ipo.gov.uk/schemas/tm";
let $text := "apple"
let $registries := ('US')

for $registry in $registries
return
  switch ($registry)
       
           case "US"
           return
           (# db:enforceindex #) {                  
                  for $db in ('US00','US01','US02')
                  for $tmUS in db:open($db)/trademark-applications-daily/application-information/file-segments/action-keys/case-file
                  where $tmUS/case-file-header/mark-identification/text() contains text { $text }
                  return $tmUS/case-file-header/mark-identification/text()
                }

            case "GB"
           return
               (# db:enforceindex #) {
                   for $tmGB in db:open('GB')/gb:MarkLicenceeExportList/gb:TradeMark
                 where $tmGB/gb:WordMarkSpecification/gb:MarkVerbalElementText/text() contains text { $text }
                 return $tmGB/gb:WordMarkSpecification/gb:MarkVerbalElementText/text()
                }

            default return "Unknown registry code"


I noticed that removing the case option "GB" ( even if it's not evaluated ), it works fine and returns the 4k records [03]: 

declare namespace gb="http://www.ipo.gov.uk/schemas/tm";
let $text := "apple"
let $registries := ('US')

for $registry in $registries
return
  switch ($registry)
 
           case "US"
           return
           (# db:enforceindex #) {                  
                  for $db in ('US00','US01','US02')
                  for $tmUS in db:open($db)/trademark-applications-daily/application-information/file-segments/action-keys/case-file
                  where $tmUS/case-file-header/mark-identification/text() contains text { $text }
                  return $tmUS/case-file-header/mark-identification/text()
                }
         
            default return "Unknown registry code"


What I'm missing here? is this the right behaviour?  

Best regards,
Sebastian

[01] https://imgur.com/o4RUUyO
[02] https://imgur.com/533c0rI
[03] https://imgur.com/mCb3qEe