The search is very defective, practically unusable

The search in the library (1st method) is extremely imprecise, in fact unusable. I have only one monitored folder, 47.000 tracks, 1.32 TB: it doesn’t update automatically, and even when I update it the search result is very bad: it doesn’t find files, single composers, titles, which are instead present in the library. Is it so difficult to have a simple and efficient search like in iTunes? It’s just a database! I’m forced to use iTunes Integrated Mode! I don’t want to be forced to look for alternative software, after years of using Audirvana…
Audirvana Mac Version 3.5.20 (3550)
macOS 10.14.6 with 16384MB RAM

A few examples might be useful.

It’s simple. if I look for a piece through a keyword, for example Beethoven’s Sonata called “Appassionata”, even if the title of the piece includes the word “Appassionata” the search does not return the file. This does not always happen, not in all cases, but there is no apparent reason why some titles are found and others are not. The synchronized folder is one and only one (with the usual criteria: artist, author, title, composer, duration, etc.). If I look for a song between 47000 and I can’t find it, in fact the search function is useless, and if I want to find everything I need I have to use iTunes Integrated Mode. I would add that the search function in iTunes is flawless! I hope I’ve explained the problem clearly enough. Thank you!

Weird… I just tried several similar searches with keywords and it seems it always returns the correct results and shows every track that contains that keyword. Of course this is just a spot check.
The only thing I can think of is maybe a problem with some of your meta-data.
Maybe post some screenshots of the album meta-data you are trying to search and the actual search results. This might help the developers to pin point the issues you are having.

or try also the three maintenance task in preferences panel.

the search in Audirvana:

the same search in iTunes:

the folder of the library is the same

no results in audirvana, 120 results in iTunes

why?

I regularly perform the three maintenance tasks

Yes, agreed. I tried some similar searches without any results returned. It seems to break down when there is some complexity.
I’m a baroque fan and and when I search for a simple ‘HWV 48’ or ‘BWV 1004’ it always seem to work nicely
Try searching for ‘op 57’ or ‘op. 57’ and you will probably get some results but I agree that there is lots of room for improvements here.

I’ve already tried, with the same result!
given the situation, for me the Audirvana library is completely unusable, also because I use the software professionally, during lectures and conferences
So I’m forced to use iTunes Integrated Mode, but the interface is the old one and frankly it’s horrible: it’s too big, you can’t resize it or customize it. In short, after years of using Audirvana I’m looking for more

I don’t know about ‘completely unusable’. I’m also using Audirvana for many years (since V1) and it never bothered me. But of course, it depends on your use case.
My library is relatively small (<1000 albums) and I can easily find my way around.
Hopefully they will improve this!

Similar feelings in my place. I reported lack of the search function many weeks ago (e.g. search results must be sortable), but nothing changes. I have to stay with iTunes, unfortunately.

Unfortunately, if you need to find a particular song (I have 47,000) during a conference and you don’t find it because Audirvana’s search engine is faulty, this makes Audirvana’s library in fact completely unusable.
No question, however, about the quality of the sound.
It would be enough for the developers to optimize the database (only 630 Mb!!!), or, if this is not possible, improve the interface of Audirvana in iTunes Integrated Mode, because the one in use is really old and horrible.