Query taking more time

Question

Iam having nearly 2 crores records at present in my table..
I want to get the avg of price from my table..
i put the query like
select avg(sum(price)) from table group by product_id
The query taking more than 5 mins to execute...
is that any other way i can simplify my query?

Answer 1

Warren:
Your first query gives:
SQL> SELECT AVG(SUM(price)) sum_price
  2  FROM t;
SELECT AVG(SUM(price)) sum_price
ERROR at line 1:
ORA-00978: nested group function without GROUP BYand your second gives:
SQL> SELECT product_id, AVG(SUM(price))
  2  FROM t
  3  GROUP BY product_id;
SELECT product_id, AVG(SUM(price))
ERROR at line 1:
ORA-00937: not a single-group group functionSymon:
What exactly are you ttrying to accomplish. Your query as posted will calculate the average of the sums of the prices for all product_id values. That is, it is equivalent to:
SELECT AVG(sum_price)
FROM (SELECT SUM(price) sum_price
      FROM t
      GROUP BY product_id)So given:
SQL> SELECT * FROM t;
PRODUCT_ID      PRICE
PROD1               5
PROD1               7
PROD1              10
PROD2               3
PROD2               4
PROD2               5The sum of the prices per product_id is:
SQL> SELECT SUM(price) sum_price
  2  FROM t
  3  GROUP BY product_id;
SUM_PRICE
        22
        12 and the average of that is (22 + 12) / 2 = 17. Is that what you are looking for? If so, then the equivalent query I posted above is at least clearer, but may not be any faster. If this is not what you are looking for, then some sample data and expected results may help. Although, it appears that you need to full scan the table in either case, so that may be as good as it gets.
John