Work Around for SQL Query 'NOT IN' that takes forever? - sql

Question

I am trying to run a query on an Oracle 10g DB to try and view 2 groups of transactions. I want to view basically anyone who has a transaction this year (2014) that also had a transaction in the previous 5 years. I then want to run a query for anyone who has a transaction this year (2014) that hasn't ordered from us in the last 5 years. I assumed I could do this with the 'IN' and 'NOT IN' features. The 'IN' query runs fine but the 'NOT IN' never completes. DB is fairly large which is probably why. Would love any suggestions from the experts!
*Notes, [TEXT] is a description of our Customer's Company name, sometimes the accounting department didn't tie this to our customer ID which left NULL values, so using TEXT as my primary grouping seemed to work although the name is obscure. CODE_D is a product line just to bring context to the name.
Below is my code:
SELECT CODE_D, sum(coalesce(credit_amount, 0) - coalesce(debet_amount,0)) as TOTAL
FROM
gen_led_voucher_row_tab
WHERE ACCOUNTING_YEAR like '2014'
and TEXT NOT IN
(select TEXT
from gen_led_voucher_row_tab
and voucher_date >= '01-JUN-09'
and voucher_date < '01-JUN-14'
and (credit_amount > '1' or debet_amount > '1')
)
GROUP BY CODE_D
ORDER BY TOTAL DESC

Answer 1

Try using a LEFT JOIN instead of NOT IN:
SELECT t1.CODE_D, sum(coalesce(t1.credit_amount, 0) - coalesce(t1.debet_amount,0)) as TOTAL
FROM gen_led_voucher_row_tab AS t1
LEFT JOIN gen_led_voucher_row_tab AS t2
ON t1.TEXT = t2.TEXT
AND t2.voucher_date >= '01-JUN-09'
AND t2.voucher_date < '01-JUN-14'
AND (credit_amount > '1' or debet_amount > '1')
WHERE t2.TEXT IS NULL
AND t1.ACCOUNTING_YEAR = '2014'
GROUP BY CODE_D
ORDER BY TOTAL DESC
ALso, make sure you have an index on the TEXT column.

Answer 2

You can increase your performance by changing the Not In clause to a Where Not Exists like as follows:
Where Not Exists
(
Select 1
From gen_led_voucher_row_tab b
Where voucher_date >= '01-JUN-09'
and voucher_date < '01-JUN-14'
and (credit_amount > '1' or debet_amount > '1')
And a.Text = b.Text
)
You'll need to alias the first table as well to a for this to work. Essentially, you're pulling back a ton of data to just discard it. Exists invokes a Semi Join which does not pull back any data at all, so you should see significant improvement.
Edit
Your query, as of the current update to the question should be this:
SELECT CODE_D,
sum(coalesce(credit_amount, 0) - coalesce(debet_amount,0)) as TOTAL
FROM gen_led_voucher_row_tab a
Where ACCOUNTING_YEAR like '2014'
And Not Exists
(
Select 1
From gen_led_voucher_row_tab b
Where voucher_date >= '01-JUN-09'
and voucher_date < '01-JUN-14'
and (credit_amount > '1' or debet_amount > '1')
And a.Text = b.Text
)
GROUP BY CODE_D
ORDER BY TOTAL DESC