On Thu, May 21, 2009 06:02, Alban Hertroys wrote:
>
> But as people often say here, premature optimisation is a waste of
> time, so don't go that route unless you have a reason to expect
> problems in that area.
>
That was my very thought when I sent that message. On the other
hand, in case I w
On May 20, 2009, at 7:17 PM, James B. Byrne wrote:
Looking at this I have to wonder what will be the effect of having
tens of thousands of rate-pairs on file. Would this query be
improved by first doing a sub-query on base/quote pairs that
returned DISTINCT pairs and then do the IN condition usi
James B. Byrne wrote:
On Wed, May 20, 2009 13:07, James B. Byrne wrote:
This seems to be working. I had to take a different approach as I
had misapprehended GROUP BY completely.
SELECT *
FROM currency_exchange_rates AS xchg1
WHERE id
IN (
SELECT id
FROM currency_exchange_rates as xc
On Wed, May 20, 2009 13:07, James B. Byrne wrote:
> This seems to be working. I had to take a different approach as I
> had misapprehended GROUP BY completely.
>
>
> SELECT *
> FROM currency_exchange_rates AS xchg1
> WHERE id
> IN (
> SELECT id
> FROM currency_exchange_rates as xchg2
>
