Querying couchbase array column

I'm not sure exactly what results you're trying to get, but first thing is that I see a syntax error: I assume you're trying to find something between two dates, but you've got a date literal, then BETWEEN then another date literal. This is not correct syntax. It would be more like BETWEEN <literal> AND <literal>.

My first guess, since you are trying to UNNEST, is maybe you are trying to do an intra-document cross join, returning the join product with the timestamps that fit within a range, which you could do like this:

SELECT a.*, t
FROM alerts a
UNNEST a.timestamps t
WHERE t BETWEEN '2018-04-21T06:37:44.512Z' AND '2018-04-21T08:37:44.512Z';

My next guess, is that if you are trying to find all alert documents where any of the timestamps fell within a certain range, this would work:

SELECT a.*
FROM alerts a
WHERE 
   ANY x IN a.timestamps
   SATISFIES (x BETWEEN '2018-04-21T06:37:44.512Z' and '2018-04-21T08:37:44.512Z')
END;

Hopefully one of those two answers will fit your needs.