Hi Michael ,
We tried dropping the below values from the function, but it did not help.
Also, the values PAID and MANUALLY PAID constitutes about 60 % of the values in table , and infact we tried creating
the partial index and it did not help.
The Strange thing is that we are trying to run this in oracle as we have done the migration recently and it is
running in less than second with same indexes and other database objects . I can understand that comparing to oracle is stupidity, but this is only thing where we can compare.
Below is the query we are running on oracle and comparing in postgres
Below is the query and plan for same
https://explain.depesz.com/s/wktl#stats
Any help would be appreciated.
Thanks and Regards,
Mukesh Kumar
Hi,
This part of the function is odd and must be dropped:
IF (ret_status = payment_rec)
THEN
ret_status := payment_rec;
I didn’t look really the function code and stopped on the view referenced by the cursor.
The view (we know it just by its name) used in the function is a black box for us. Perhaps it is important to begin optimization there!
If values 'PAID' and 'MANUALLYPAID' are an important percentage of table rows forcing index use is not a good thing especially when it is done with a non-optimized function.
If rows with values 'PAID' and 'MANUALLYPAID' constitute a little percentage of the table, then the partial index plus rewriting the query would be much more efficient
Select
payment_sid_c,
lms_app.translate_payment_status(payment_sid_c) as paymentstatus
from
lms_app.lms_payment_check_request
where
lms_app.translate_payment_status(payment_sid_c) IN ('PAID', 'MANUALLYPAID')
group by
payment_sid_c
If not, you can gain some performance if you rewrite your query to be like this:
Select
payment_sid_c,
lms_app.translate_payment_status(payment_sid_c) as paymentstatus
from
lms_app.lms_payment_check_request
group by
payment_sid_c
having
lms_app.translate_payment_status(payment_sid_c) IN ('PAID', 'MANUALLYPAID')
And you can also try to write the query like this:
Select t.payment_sid_c, lms_app.translate_payment_status(t.payment_sid_c)
From
(
Select
payment_sid_c
from
lms_app.lms_payment_check_request
group by
payment_sid_c
having
lms_app.translate_payment_status(payment_sid_c) IN ('PAID', 'MANUALLYPAID')
) t
Regards
Hi Rainer ,
We tried to create the partial ‘index on table but it did not help, and it is taking approx. 7 sec now.
Also we tried to force the query to use the index by enabling the parameter at session level
set enable_seqscan=false;
and it is still taking the time below is the explain plan for the same
https://explain.depesz.com/s/YRWIW#stats
Also we running the query which is actually used in application and above query is used in below query. Below
is the explain plan for same.
https://explain.depesz.com/s/wktl#stats
Please assist
Thanks and Regards,
Mukesh Kuma
Hi Team,
We are running the below query in PostgreSQL and its taking approx. 8 to 9 sec to run the query.
Query – 1
Select * from
(
Select payment_sid_c,
lms_app.translate_payment_status(payment_sid_c) AS paymentstatus
from
lms_app.lms_payment_check_request
group by payment_sid_c) a
where paymentstatus in ('PAID', 'MANUALLYPAID')
The explain plan and other details are placed at below link for more information. We have checked the indexes on column but in the explain plan it is showing as Seq Scan which we
have to find out.
https://explain.depesz.com/s/Jsiw#stats
This query is using a function translate_payment_status on column payment_sid_c whose script is attached in this mail
Could please anyone help or suggest how to improve the query performance.
You can try create a partial index that help this filter:
Filter: ((lms_app.translate_payment_status(payment_sid_c))::text = ANY ('{PAID,MANUALLYPAID}'::text[]))
