Thank you, this works like a charm.
On 2015年1月4日周日 20:01 Andreas Kretschmer wrote:
> Flyingfox Lee wrote:
>
> > I am doing a `group by` on a table with ~ 3 million rows, the code is
> simply
> > `select A, B, C, D,E count(1) from t group by A, B, C, D, E order by
> 6`, it
> > takes ~ 3 minutes
Flyingfox Lee wrote:
> I am doing a `group by` on a table with ~ 3 million rows, the code is simply
> `select A, B, C, D,E count(1) from t group by A, B, C, D, E order by 6`, it
> takes ~ 3 minutes for this operation and there are ~ 500 rows returned. So, to
> speed this up, should I add a compo
I am doing a `group by` on a table with ~ 3 million rows, the code is
simply `select A, B, C, D,E count(1) from t group by A, B, C, D, E order by
6`, it takes ~ 3 minutes for this operation and there are ~ 500 rows
returned. So, to speed this up, should I add a composite index on A, B, C,
D, E or
