Resegment occurs everytime

Hi,

i have 2 tables and has very less data ....but when i am doing the Explain plan on joining two tables it is saying the Resegment(outer) and Resegment(Inner).Both are using the super projection and joining also on same daat typ column.

QUERY PLAN DESCRIPTION:
------------------------------

explain with a as ( select a,b from "263723_egbw_rvcpoc".a2 where a=2 ),b as ( select a,b from "263723_egbw_rvcpoc".b2) select a1.a,a1.b,b1.a,b1.b from a a1 left join b b1 on a1.a=b1.a;

Access Path:
+-JOIN MERGEJOIN(inputs presorted) [LeftOuter] [Cost: 59, Rows: 11] (PATH ID: 1) Outer (RESEGMENT) Inner (RESEGMENT)
| Join Cond: (a1.a = b1.a)
| Execute on: All Nodes
| +-- Outer -> SELECT [Cost: 24, Rows: 1] (PATH ID: 2)
| | Execute on: All Nodes
| | +---> STORAGE ACCESS for a2 [Cost: 24, Rows: 1] (PATH ID: 3)
| | | Projection: 263723_egbw_rvcpoc.a2_b0
| | | Materialize: a2.a, a2.b
| | | Filter: (a2.a = 2)
| | | Execute on: All Nodes
| +-- Inner -> SELECT [Cost: 33, Rows: 11] (PATH ID: 4)
| | Execute on: All Nodes
| | +---> STORAGE ACCESS for b2 [Cost: 33, Rows: 11] (PATH ID: 5)
| | | Projection: 263723_egbw_rvcpoc.b2_b0
| | | Materialize: b2.a, b2.b
| | | Execute on: All Nodes

Projections used

263723_egbw_rvcpoc.b2_b0

CREATE PROJECTION "263723_egbw_rvcpoc".b2_b0 /*+basename(b2),createtype(L)*/
(
a,
b
)
AS
SELECT b2.a,
b2.b
FROM "263723_egbw_rvcpoc".b2
ORDER BY b2.a,
b2.b
SEGMENTED BY hash(b2.a, b2.b) ALL NODES OFFSET 0;

CREATE PROJECTION "263723_egbw_rvcpoc".a2_b0 /*+basename(a2),createtype(L)*/
(
a,
b
)
AS
SELECT a2.a,
a2.b
FROM "263723_egbw_rvcpoc".a2
ORDER BY a2.a,
a2.b
SEGMENTED BY hash(a2.a, a2.b) ALL NODES OFFSET 0;

Just wanted to know why Outer (RESEGMENT) Inner (RESEGMENT) both occurs even if projection columns are sorted.