Mechanics of synonym in search

[drk4]

I just wanted to check how synonyms work specifically.

I've set up one for the following

regex
\b([Oo]ne [Dd]rive)\b

transforms to
[onedrive "one drive"]

so if you search for 'one drive' it will also search for 'onedrive'

However the total set of results is now far fewer with this enabled, compared to what was appearing previously for searches for 'one drive'

Is this because the transform has "one drive" in quotes so these two words must then appear together in the transformed search?
So the synonym rule is having the side-effect that searching for 'one drive' wont match these two keywords unless they now appear adjacent, when previously that wouldnt have been the case?

[plevan]

You are correct - before you put the synonym in place any matching result would include either of the words one and drive or both words (unless you had the -fmo option specifying fully matching results only) - but it didn't matter where in the text these words appeared.

Placing double quotes around the query treats the term "one drive" as a single word and will only match if the words are adjacent (and in the same order). This is called a phrase match.

If you want the same behaviour as before remove the quotes from your synonym expansion so you have

one drive -> [onedrive one drive] but the expansion you have is probably more accurate for what you want .

Full details of the query language are available in the documentation at: https://docs.funnelback.com/15.20/develop/reference-documents/query-language-help.html