Optimizing query with huge amount of data - sql-server

Question

How can I optimize the query. I looked at the execution plan and created all the index. Every table has huge data. And this query execution time is very large. By looking at the query could you please suggest where can I optimize more.
If I give little background of the query the structure like:
There are many companies
Each company can have multiple managers
Data is in pagination format
Filter on #parent_manager so another temp table created parent_manager_filter just to use for the filtering purpose as #parent_manager has name in "," separated format
CREATE TABLE #parent_manager
(
cid NUMERIC(18) PRIMARY KEY,
name NVARCHAR(MAX),
code NVARCHAR(MAX)
);
CREATE INDEX cte_parent_manager ON #parent_manager(cid);
CREATE TABLE #parent_manager_filter
(
cid NUMERIC(18),
name NVARCHAR(1000),
code NVARCHAR(1000)
);
CREATE INDEX cte_parent_manager_filter_idx ON #parent_manager_filter(cid);
INSERT INTO #parent_manager
SELECT DISTINCT
mgrc.cid,
name = CAST (STUFF ((SELECT ', ' + CAST(c.company_name AS varchar(2000))
FROM manager_company mc
INNER JOIN company c ON (mc.mgr_cid = c.cid )
WHERE mc.cid = mgrc.cid
AND c.company_name IS NOT NULL
FOR XML PATH ('')), 1, 1, '') AS VARCHAR(2000)),
code = CAST (STUFF ((SELECT ', ' + CAST(c.code AS varchar(2000))
FROM manager_company mc
INNER JOIN company c ON (mc.mgr_cid = c.cid )
WHERE mc.cid = mgrc.cid
AND c.company_name IS NOT NULL
FOR XML PATH ('')), 1, 1, '') AS VARCHAR(2000))
FROM
manager_company mgrc
INNER JOIN
company c ON (mgrc.mgr_cid = c.cid )
JOIN
handler h ON (c.handlerId = h.handlerid )
WHERE
h.handlerid = 5800657002370
INSERT INTO #parent_manager_filter
SELECT DISTINCT
mc.cid,
c.company_name as name,
c.code as code
FROM
manager_company mc
INNER JOIN
company c ON (mc.mgr_cid = c.cid )
JOIN
handler h ON (h.handlerid = c.handlerid)
WHERE
h.handlerid = 5800657002370 ;
WITH company AS
(
SELECT DISTINCT
c.cid AS cid,
parentManager.name AS MANAGER_NAME,
parentManager.code AS code
FROM
company c
LEFT JOIN
#parent_manager parentManager ON (parentManager.cid = c.cid)
LEFT JOIN
# parent_manager_filter parentManagerFilter ON (parentManagerFilter.cid = c.cid)
WHERE
parentManagerFilter.name IN (:managerList)
),
total_rows AS
(
SELECT
COUNT(*) OVER () AS TOTALCOUNT,
ROW_NUMBER() OVER (ORDER BY company_name ASC) AS rnum,
grid.*
FROM
company grid
)
SELECT *
FROM total_rows rnum
WHERE rnum >= 1
AND rnum <= 10
DROP TABLE #parent_manager;
DROP TABLE #parent_manager_filter;

Answer 1

If you are building up temp tables then I would make sure you don't miss a clustered index, else your temp table is simply a heap. You don't have one covering the filter table.
INSERT INTO #parent_manager_filter ...
CREATE CLUSTERED INDEX cte_parent_manager_filter On #parent_manager_filter(cid);