Query help - distinct

Question

Is there a more efficient way to write this query besides using DISTINCT? 
I’m trying to count the number of unique account numbers by each INT. 
My query works but it’s a little slow. 
SELECT
act.INT
,COUNT(DISTINCT(plm.ACCT_NUMBER)) ACCT#
FROM…
 GROUP BY act.INT
Any information would be greatly appreciated.
Thanks,
x

Answer 1

Please follow basic Netiquette and post the DDL we need to answer this. Follow industry and ANSI/ISO standards in your data. You should follow ISO-11179 rules for naming data elements. You should follow ISO-8601 rules for displaying temporal data. We need
to know the data types, keys and constraints on the table. Avoid dialect in favor of ANSI/ISO Standard SQL. 
And you need to read and download the PDF for: 
https://www.simple-talk.com/books/sql-books/119-sql-code-smells/
>> Is there a more efficient way to write this query besides using DISTINCT?  I’m trying to count the number of unique account numbers by each INT.  My query works but it’s a little slow. <<
The INT is a reserved word (INTEGER) in SQL so it should never be a column name. Using special symbols like # in a data element name is another serious ISO violation and awful programming. Use only Latin letters, digits and the minimal set of punctuation marks
from the common Unicode subset. This will let yuou use the same data element names in all the ISO standard languages zand tooils. 
If you have the right indexes, the COUNT(DISTINCT <expr>) should perform fine. 
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in Sets / Trees and Hierarchies in SQL