Here is a summary of reproducible results for TEST_QUERY_VERSION on my server using 2.0.3.11.
3 and 4 give absolutely terrible results, backup sets need 1 to 4 hours instead of a few minutes for all backup sets.
1 gives about usual (2.0.3.5 and earlier) results +20% except for the music library.
2 gives best results and likely has a short edge over previous results except for the music library.
For all cases and backup sets expect the music library “opened files” is close to none, likely corresponding to modified files.
For the music library which did not change over the tests, opened files is 25372 out of 60229 examined files. For value 1 and 2 this gives 3 to 4 hours instead of less than 10min on 2.0.3.5.
Could the 25372 opened files be the result of a change in 2.0.3.11 or of a damaged database? should I test something on the database?