Re: 2 Selects 1 is faster, why?

Hi,

-- Eric <emayo(at)pozicom(dot)net> wrote:

> If I perform the following 2 selects, the first one is EXTREMELY slow
> where the 2nd one is very fast.

[...]

> Why would 2 be so much faster? I have ran the EXPLAIN on this and index
> scans are being used.

I guess, the first query has to search for all ol.orderid the equivalent
o.orderid; the second variant only has to search for '1234' in each
?.orderid, which is much faster.

Explizit joins should speed up this!

> NOTE: The actual queries return more information than this, but the
> fundamental change shown above seems to give me the instant response I am
> looking for. (1) takes about 60 seconds to run and (2) takes 3-5 seconds
> to run.

3-5 seconds seems very long to me, if indexes are used and the result is
not a set of thousands of rows; are you sure?

Ciao
Alvar

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