RE: SQL - Using SELECT FROM x physical table

How about an index on the YYYY part of the date?

CREATE INDEX index_name ON table_name(to_char(date_column, 'yyyy'));

On a test table with 500,000 rows, the plan for:

SELECT count(*)
FROM my_table
WHERE to_char(my_date, 'yyyy') = (
  SELECT to_char(max(my_date), 'yyyy')
  FROM norman
);

gives me a full scan on the max() part but an index range scan for the select part using my function based index.

Another alternative would be to partition on the year and that should reduce the amount of data being read as only one partition would need to be read.

Cheers,
Norm.

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