Summation graph over tree in PostgreSQL - postgresql

Question

I have salaries table and a tree with departments (child, parent). Need to go over the graph and calculate every summation vertex. The output I need - summation of all child nodes. The issue looks like the request is double counting values.
Test data:
CREATE TABLE deps (
id serial,
child varchar,
parent varchar);
CREATE TABLE salaries (
name varchar,
salary numeric);
INSERT INTO salaries(name, salary) VALUES
('manager1', 100),
('manager2', 100),
('manager3', 100),
('manager4', 100),
('manager5', 100),
('manager6', 100),
('manager7', 100),
('manager8', 100),
('manager9', 100),
('engeneer1', 100),
('engeneer2', 100),
('engeneer3', 100),
('engeneer4', 100),
('engeneer5', 100),
('engeneer6', 100),
('engeneer7', 100),
('engeneer8', 100),
('engeneer9', 100),
('engeneer10', 100),
('accountant1', 100),
('accountant2', 100),
('accountant3', 100),
('accountant4', 100);
insert INTO deps(child, parent) VALUES
('manager1', 'management'),
('manager2', 'management'),
('manager3', 'management'),
('manager4', 'management'),
('management_team1', 'management'),
('management_team1_1', 'management_team1'),
('management_team1_2', 'management_team1'),
('manager5', 'management_team1_1'),
('manager6', 'management_team1_1'),
('manager7', 'management_team1'),
('manager8', 'management_team1_2'),
('manager9', 'management_team1_2'),
('engeneer1', 'it'),
('engeneer2', 'it'),
('engeneer3', 'it'),
('engeneer4', 'it'),
('it_dep1', 'it'),
('it_dep2', 'it'),
('engeneer5', 'it_dep1'),
('engeneer6', 'it_dep1'),
('engeneer7', 'it_dep2'),
('engeneer8', 'it_dep2'),
('it_dep3', 'it_dep2'),
('engeneer9', 'it_dep3'),
('engeneer10', 'it_dep3'),
('accountant1', 'accounts'),
('accountant2', 'accounts'),
('accountant3', 'accounts'),
('accountant4', 'accounts'),
('management', NULL),
('accounts', NULL),
('it', NULL);
Request:
WITH RECURSIVE tree ("depth", parent, child) as(
SELECT
0,
parent,
child
FROM deps
WHERE parent IS NULL
UNION
SELECT
"depth" + 1,
tree.child,
deps.child
FROM tree JOIN deps ON tree.child = deps.parent
),
graph (child, parent, "depth", value) as(
-- non recursive
SELECT
tree.child,
tree.parent,
tree."depth",
salaries.salary -- outbound amount FROM node which IS equal TO salary AT this depth
FROM
tree JOIN salaries ON salaries.name = tree.child
WHERE tree."depth" = (SELECT max("depth") FROM tree) -- we START FROM deepest LEVEL OF yierarchy
UNION
-- recursive
SELECT
current_tree.child,
current_tree.parent,
current_tree."depth",
COALESCE(current_tree.salary,
sum(graph.value) OVER (PARTITION BY current_tree.child)
) -- outbound amount FROM node which IS equal TO SUM of ALL incoming amounts
FROM
graph,
LATERAL (SELECT * FROM tree LEFT JOIN salaries ON salaries.name = tree.child WHERE tree."depth" = graph."depth" - 1) AS current_tree
LEFT JOIN LATERAL (SELECT * FROM tree WHERE tree."depth" = graph."depth") AS previous_tree
ON current_tree.child = previous_tree.parent
-- WHERE graph."depth" = (SELECT max("depth") FROM graph)
)
SELECT * FROM graph
WHERE graph."depth" = (SELECT max("depth") FROM graph)
gives error since double calling of graph table is not allowed
DB Fiddle sample
I expect to see 32 relations corresponding to initial tree with sums as values of all child nodes.