Re: a JOIN to a VIEW seems slow

On Thu, Sep 21, 2017 at 3:54 PM, Merlin Moncure wrote:
>
> > On Thu, Sep 21, 2017 at 1:51 AM, Frank Millman <frank(at)chagford(dot)com> wrote:
> >
> > I did not get any response to this, but I am still persevering, and feel
> > that I am getting closer. Instead of waiting 26 minutes for a result, I
> > realise that I can learn a lot by using EXPLAIN. This is what I have found
> > out.
>
> Something is not adding up here. Can you EXPLAIN ANALYZE the 26 minute query?
>

I’m working on it, but my machine is playing up and it is getting late, so I will try again tomorrow.
A passing comment – the 26 minute query is more complex, so will need some explaining (no pun intended). I was hoping that my simplified example would illustrate what I think is the problem.
Anyway, here is the query -
SELECT q.cust_row_id,
SUM(CASE WHEN q.tran_date > '2015-08-31' THEN q.balance ELSE 0 END
) AS "balance_curr AS [DECTEXT]",
SUM(CASE WHEN q.tran_date <= '2015-08-31' AND q.tran_date > '2015-07-31' THEN q.balance ELSE 0 END
) AS "balance_30 AS [DECTEXT]",
SUM(CASE WHEN q.tran_date <= '2015-07-31' AND q.tran_date > '2015-06-30' THEN q.balance ELSE 0 END
) AS "balance_60 AS [DECTEXT]",
SUM(CASE WHEN q.tran_date <= '2015-06-30' AND q.tran_date > '2015-05-31' THEN q.balance ELSE 0 END
) AS "balance_90 AS [DECTEXT]",
SUM(CASE WHEN q.tran_date <= '2015-05-31' THEN q.balance ELSE 0 END
) AS "balance_120 AS [DECTEXT]"
FROM
(SELECT
due_trans.cust_row_id,
due_trans.tran_date,
trans_due.amount_cust +
COALESCE((SELECT SUM(trans_alloc.alloc_cust+trans_alloc.disc_cust)
FROM prop.ar_trans_alloc trans_alloc
LEFT JOIN prop.ar_trans alloc_trans ON
alloc_trans.tran_type = trans_alloc.tran_type
AND alloc_trans.tran_row_id = trans_alloc.tran_row_id
WHERE trans_alloc.due_row_id = trans_due.row_id
AND alloc_trans.tran_date <= '2015-09-30'
), 0)
AS balance
FROM prop.ar_trans_due trans_due
LEFT JOIN prop.ar_trans due_trans ON
due_trans.tran_type = trans_due.tran_type
AND due_trans.tran_row_id = trans_due.tran_row_id
WHERE due_trans.tran_date <= '2015-09-30'
) AS q
GROUP BY q.cust_row_id
ORDER BY q.cust_row_id;

I will report back with the EXPLAIN ANALYSE tomorrow.

Frank