Return Table Type from A function in PostgreSQL

Question

I have a function from which has a return type as TABLE, and I want to get certain columns from my table into that RETURN TABLE type for my functionality. When I execute the

Answer 1

Your function is doing a lot of empty work.

You could simplify with a FOR loop with implicit cursor instead of the more tedious and expensive explicit cursor.
On a closer look it turns out you don't need any of this at all. Radically simplify with a simple query. I wrapped it into an SQL function:

CREATE OR REPLACE FUNCTION ccdb.fn_email_details_auto()
  RETURNS TABLE (code integer, area smallint, action smallint, flag smallint
               , ucount integer, view_cnt integer) AS
$func$

SELECT u.section_code, u.ddu_area, u.ddu_action, u.status_flag
     , u.ccdb_ucount, u.ccdb_view_cnt
FROM   ccdb.update_qtable u
WHERE  u.entry_time >= now()::date - 1
AND    u.entry_time <  now()::date        -- sargable!
ORDER  BY u.section_code, u.ddu_area, u.ddu_action;

$func$  LANGUAGE sql;

Should be much faster while returning the same.
Also, use this:

WHERE  u.entry_time >= now()::date - 1
AND    u.entry_time <  now()::date

instead of:

WHERE entry_time::date = now()::date - interval '1 day'

The alternative is sargable and can use a plain index on entry_time, which should be crucial for performance.