User Defined Function performance tuning PostgreSQL - postgresql

Question

I have the following function which is taking around 6secs time to complete the execution on 25,000 records.
Function:
CREATE OR REPLACE FUNCTION public.fun_getData
(
p_pin VARCHAR(15),
p_datetime TIMESTAMP
)
RETURNS NUMERIC(5,1)
AS
$BODY$
DECLARE v_pfcode VARCHAR(20);
DECLARE v_starttime TIMESTAMP;
DECLARE v_endtime TIMESTAMP;
DECLARE v_num NUMERIC(5,2);
DECLARE v_gpdata NUMERIC(5,2);
DECLARE v_timedata NUMERIC(5,2);
DECLARE v_sales VARCHAR(10);
BEGIN
SELECT col_sale INTO v_sales FROM public.tbl_Sales WHERE sales_id ='A01';
IF v_sales = '-'
THEN
RETURN 0;
END IF;
SELECT pfcode, gpdata INTO v_pfcode,v_gpdata
FROM public.tbl_fdata
WHERE fpin=p_pin;
v_gpdata := COALESCE(v_gpdata,0);
IF v_pfcode IS NULL
THEN
RETURN v_gpdata;
END IF;
SELECT StartTime, EndTime, num INTO v_starttime,v_endtime,v_num
FROM public.salesyears
WHERE s_pfcode =v_pfcode AND y.year = date_part('year',p_datetime);
IF v_starttime IS NULL OR v_endtime IS NULL
THEN
RETURN v_gpdata;
END IF;
IF v_starttime < v_endtime
THEN
IF p_datetime >= v_starttime AND p_datetime < v_endtime THEN
v_timedata := v_gpdata + v_num;
ELSE
v_timedata := v_gpdata;
END IF;
ELSE
IF p_datetime >= v_endtime AND p_datetime < v_starttime THEN
v_timedata := v_gpdata;
ELSE
v_timedata := v_gpdata + v_num;
END IF;
END IF;
RETURN v_timedata;
END;
$BODY$
LANGUAGE plpgsql;
Function Call:
select 120*public.fun_getData(col_pin, modifieddate)
from public.tbl_prddata
where code = 'XMOP';
Taking around 00:00:06 time to execute.
Note: Same function I have created in SQL Server environment on same data set, it gets executed with second.
Execution Plan: explain(analyze,verbose,buffers)
"Seq Scan on public.tbl_prddata (cost=0.00..8141.61 rows=23647 width=32) (actual time=0.253..5970.663 rows=25011 loops=1)"
" Output: ('120'::numeric * public.fun_getData((col_pin)::character varying, (modifieddate)::timestamp without time zone))"
" Filter: ((tbl_prddata.code)::sys.""varchar"" = 'XMOP'::sys.""varchar"")"
" Rows Removed by Filter: 86508"
" Buffers: shared hit=116845"
"Query Identifier: 5592079453045444499"
"Planning Time: 0.076 ms"
"Execution Time: 5980.916 ms"
Edit: Added more execution plan's:
Query 1:
EXPLAIN(ANALYZE, VERBOSE, BUFFERS)
SELECT col_sale FROM public.tbl_Sales WHERE sales_id ='A01';
--Output:
"Index Scan using idx_tbl_Sales_colob on public.tbl_Sales (cost=0.14..8.16 rows=1 width=7) (actual time=0.250..0.251 rows=1 loops=1)"
" Output: col_sale"
" Index Cond: ((tbl_Sales.sales_id)::sys.""varchar"" = 'A01'::sys.""varchar"")"
" Buffers: shared hit=9"
"Query Identifier: 6306884246769163476"
"Planning:"
" Buffers: shared hit=50"
"Planning Time: 0.183 ms"
"Execution Time: 0.266 ms"
Query 2:
EXPLAIN(ANALYZE, VERBOSE, BUFFERS)
SELECT pfcode, gpdata FROM public.tbl_fdata WHERE fpin='PRD01';
--Output:
"Index Scan using idx_tbl_fdata_colx on public.tbl_fdata (cost=0.12..8.14 rows=1 width=46) (actual time=0.027..0.027 rows=1 loops=1)"
" Output: pfcode, gpdata"
" Index Cond: ((tbl_fdata.fpin)::sys.""varchar"" = 'PRD01'::sys.""varchar"")"
" Buffers: shared hit=2"
"Query Identifier: -4137289472330654813"
"Planning:"
" Buffers: shared hit=655"
"Planning Time: 1.415 ms"
"Execution Time: 0.047 ms"
Query 3:
EXPLAIN(ANALYZE, VERBOSE, BUFFERS)
SELECT StartTime, EndTime, num
FROM public.salesyears
WHERE s_pfcode ='all' AND year = date_part('year','2023-01-01 00:20:00');
--Output:
"Seq Scan on public.salesyears y (cost=0.00..1.47 rows=1 width=30) (actual time=0.064..0.064 rows=0 loops=1)"
" Output: StartTime, EndTime, num"
" Filter: (((s_pfcode)::sys.""varchar"" = 'all'::sys.""varchar"") AND ((year)::double precision = '2023'::double precision))"
" Rows Removed by Filter: 27"
" Buffers: shared hit=1"
"Query Identifier: 7071532767670856741"
"Planning:"
" Buffers: shared hit=56"
"Planning Time: 0.280 ms"
"Execution Time: 0.074 ms"
Query 4:
explain(analyze,verbose,buffers)
select * from public.tbl_prddata
where code= 'XMOP';
--Output:
"Seq Scan on public.tbl_prddata (cost=0.00..2372.74 rows=22847 width=263) (actual time=0.075..104.757 rows=23031 loops=1)"
" Output: cola,colb,colc,cold,cole,colf,colg,colh"
" Filter: ((tbl_prddata.code)::sys.""varchar"" = 'XMOP'::sys.""varchar"")"
" Rows Removed by Filter: 31588"
" Buffers: shared hit=1690"
"Query Identifier: 7714647889345744025"
"Planning Time: 0.093 ms"
"Execution Time: 106.360 ms"