Dear Solr Team
What happens when you send a partial document update like the following?
{
"id":"mydoc",
"price":{"set":99}
}
but no document with the id "mydoc" exists at this moment.
Or what happens if the partial document update is missing the id field?
Or what happens if you send a mixed request, containing fields with modifiers
and fields containing only the value?
{
"id":"mydoc",
"name": "product",
"price":{"set":99}
}
I personally know that in the first case it acts as an upsert. so inserting the
document if its missing, and updating it if it already exists.
And in the second case it always inserts a new document, with its id being
generated.
For the third case I am not entirely sure, but I think if there is at least one
field in the request with a modifier the whole request acts as a partial
document update and fields without modifiers are handled as if they have the
modifier "set". Thats what the behaviour on solr 9.10.1 looks like at least.
The Documentation does not really explain any of the above cases clearly. This
also leads to AI making very questionable statements that are just wrong.
https://share.google/aimode/rZE2udrRajAUNDD6y
Google just casually tells us that it only acts as an upsert but ONLY if the
document already exists in the collection, which is wrong and also does not
make any sense as that would not be an upsert.
https://chatgpt.com/s/t_6a69f66582dc81919da8e03451e267f1
Also Chatgpt is just wrong about it.
As far as I understand it, partial document updates were introduced in solr 4
and the upsert behaviour was introduced in solr 4.1. but as its not clearly
documented I am not 100% sure.
https://stackoverflow.com/questions/14886814/can-solr-perform-an-upsert#comment21025920_14888083
Kind Regards
