I've worked out how to get some rows from a table where a column has the lowest possible value. Note this can return multiple rows, which is what I want. It works just fine.
SELECT col1, col2 FROM TableA WHERE col4=0 AND col5=1 AND col3 IN (SELECT MIN(col3) FROM TableA WHERE col4=0 AND col5=1)
But is the nested select overkill, i.e. can this be optimised? Maybe there's a simple SQL command I'm missing...
SELECT col1, col2, MIN(col3) FROM TableA WHERE col4=0 AND col5=1
but this will only ever return one row.