3 ms·
I think hash index help in join as well. "where table1.c1 = table2.c2" A hash index on c2 would let the join be done in O(n) of c1 + O(1) of c2.
by ww520 9y ago
I think hash index help in join as well. "where table1.c1 = table2.c2" A hash index on c2 would let the join be done in O(n) of c1 + O(1) of c2.