Check that sort fields on all indices are compatible

[scampi]

Close #73146

[elasticmachine]

Pinging @elastic/es-search (Team:Search)

[scampi]

Is a different solution being considered for this ?

[cbuescher]

Hi @scampi, thanks for working on this issue and apologies for the late response, this somehow fell through the cracks.
After taking a look at the issue in #73146 and the proposed fix now, I'm afraid that the proposed solution of comparing DocValueFormats Writable name might break some sort behaviour between types that currently works, while it might not be enough to prevent ClassCast exceptions for other types.
For example sorting across “keyword” and “version” type entries in different indices currently works, although the result might not always be expected (the special sorting of version fields is most likely not honoured), while e.g. mixing “double” and “float” numeric types still leads to a “class_cast_exception”, so it isn’t caught earlier by the modification to the
“validateMergeSortValueFormats” method.
I’m currently unsure where the best place to fix this would be and what kind of sorting behaviour between different mapping types we want to support, but I’ll hopefully get some info on this soon. Will either reply here or on the original issue.

[elasticsearchmachine]

Pinging @elastic/es-search-relevance (Team:Search Relevance)