Maybe we can remove it from the grammar? I think that the plan was to use "/" for division with fractional results and "DIV" for integer division.

MB-27565 proposes to add DIV and MOD operators with DIV being an integer division.
So we don't need an IDIV operator - it needs to be removed from the grammar.
Also the current "/" operator provides an integer division - we should change it to return a fractional result (like in the Query Service).

CBAS "/" operator is aligned with the Query Service's "/" operator.
Query service does not have DIV, IDIV operators but has DIV() and IDIV() functions (and ADD(), IMOD(), MOD(), MULT(), NEG(), SUB()) Should CBAS also implement those?
See https://github.com/couchbase/query/tree/master/expression

Re-triage issues for the next release.

DIV(), IDIV(), ADD(), IMOD(), MOD(), MULT(), NEG(), and SUB() are internal function that are not exposed to the user, so no further alignment is necessary.

Till Westmann since there is no code change, can we just close this issue?

Yes, closed.