Hi @rahul1 we are facing an issue with Observation focus reference being empty while creating an Observation . we use

focus

field to link a Condition to an Observation , we found a bug (a race condition) in our system which sets reference to undefined

{
... observation ,
focus: [{reference: undefined}]
}

on Medplum this is being stored as

{
...observation,
focus: [{}]
}

problem with this is when use the search filter

focus:missing=true

these does not show up as the array has an empty object in it . i have also tried using

focus:contains={}

even that does not return anything . currently i use

focus:missing=false&sort=-focus

to sort and get these kinda values on top . but i remember from our previous conversation when doing batch queries sorting is not good and we cant find a way to query just these values. do you have any suggestions ?

Sorting can be fine for batch queries. My previous comment was in regards to "Upsert" call - in that case, the sorting doesn't matter b/c we are just looking for a single entry

cool thanks for the update. but what is the most efficient way for us to query these particular records ?