Let
π
{\mathscr{A}}
be an abelian category having enough projective and injective objects,
and let
π―
{\mathscr{T}}
be an additive subcategory of
π
{\mathscr{A}}
closed under direct summands.
A known assertion is that in a short exact sequence in
π
{\mathscr{A}}
, the
π―
{\mathscr{T}}
-projective
(resp.
π―
{\mathscr{T}}
-injective) dimensions of any two terms can sometimes induce an upper
bound of that of the third term by using the same comparison expressions. We show that
if
π―
{\mathscr{T}}
contains all projective (resp. injective) objects of
π
{\mathscr{A}}
, then
the above assertion holds true if and only if
π―
{\mathscr{T}}
is resolving (resp. coresolving).
As applications, we get that a left and right Noetherian ring R is n-Gorenstein if and only if
the Gorenstein projective (resp. injective, flat) dimension of any left R-module is
at most n. In addition, in several cases, for a subcategory
π
{\mathscr{C}}
of
π―
{\mathscr{T}}
,
we show that the finitistic
π
{\mathscr{C}}
-projective and
π―
{\mathscr{T}}
-projective dimensions of
π
{\mathscr{A}}
are identical.