Unanswered: Tune a query with where clause that has a function
We have a query extracting data from a database that looks something like
Select * from <tablename>
WHERE SUBSTR(ACCT_TYPE) IN (a,b,c,d)
The table has more than 50 million records. The connector takes a very long time to read this data. In 1.5 hours, it managed to read only 1.5 million rows. Any advise on how to tune this query? We have an index on ACCT_TYPE.