On 9/30/2014 4:50 PM, Jonathan Vanasco wrote:
WHERE (col_1 IS NULL ) AND (col_2 IS NULL) AND ((col_3 IS NULL) OR (col_3 = col_1))
if col_1 IS NULL, then that OR condition doesn't make much sense. just saying...
these 4 columns are all nullable booleans, so they can be TRUE, FALSE, or NULL ? with 4 columns, there's 3^4 = 81 possible combinations of these values... you might get better speeds encoding this as a single SHORT INTEGER, and enumerating those 81 states, then just do equals or IN (set of values) conditions... of course, this might make a lot of OTHER code more complicated. It might be easier to make each col_X 2 bits of this integer, such that one bit indicates the value was 'NULL', and the other bit is the true/false state if that first bit isn't set, this would make testing individual bits somewhat better.
-- john r pierce 37N 122W somewhere on the middle of the left coast -- Sent via pgsql-general mailing list (pgsql-general@xxxxxxxxxxxxxx) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-general
