Thread: Migration to version 7.4

Migration to version 7.4

From
Nabil Sayegh
Date:
Hi all,

congratulations to the new release, I couldn't try it yet, but the release
notes are promising.

However there is one thing that needs a bit more explanation:

1) Inner joins using the explicit JOIN syntax may behave differently
because they are now better optimized.

What exactly do you mean by 'may behave differently'?

Could you give an example?

I excessively use explicit JOINs because I like the syntax much more as it
seperates the 'building of the superset of the result' from the 'filtering'.

TIA
--
  e-Trolley Sayegh & John, Nabil Sayegh
  Tel.: 0700 etrolley /// 0700 38765539
  Fax.: +49 69 8299381-8
  PGP : http://www.e-trolley.de


Re: Migration to version 7.4

From
Bruce Momjian
Date:
Nabil Sayegh wrote:
> Hi all,
>
> congratulations to the new release, I couldn't try it yet, but the release
> notes are promising.
>
> However there is one thing that needs a bit more explanation:
>
> 1) Inner joins using the explicit JOIN syntax may behave differently
> because they are now better optimized.
>
> What exactly do you mean by 'may behave differently'?

They will be fully optimized, so they might be faster.  In pre-7.4, ANSI
syntax restricted the choices researched by the optimizer.

--
  Bruce Momjian                        |  http://candle.pha.pa.us
  pgman@candle.pha.pa.us               |  (610) 359-1001
  +  If your life is a hard drive,     |  13 Roberts Road
  +  Christ can be your backup.        |  Newtown Square, Pennsylvania 19073

Re: Migration to version 7.4

From
Nabil Sayegh
Date:
Bruce Momjian wrote:
>>1) Inner joins using the explicit JOIN syntax may behave differently
>>because they are now better optimized.
>>
>>What exactly do you mean by 'may behave differently'?
>
>
> They will be fully optimized, so they might be faster.  In pre-7.4, ANSI
> syntax restricted the choices researched by the optimizer.

That's fine, but more important to me is if I need to change any queries in
my apps ;)

tfyh
--
  e-Trolley Sayegh & John, Nabil Sayegh
  Tel.: 0700 etrolley /// 0700 38765539
  Fax.: +49 69 8299381-8
  PGP : http://www.e-trolley.de


Re: Migration to version 7.4

From
Bruce Momjian
Date:
Nabil Sayegh wrote:
> Bruce Momjian wrote:
> >>1) Inner joins using the explicit JOIN syntax may behave differently
> >>because they are now better optimized.
> >>
> >>What exactly do you mean by 'may behave differently'?
> >
> >
> > They will be fully optimized, so they might be faster.  In pre-7.4, ANSI
> > syntax restricted the choices researched by the optimizer.
>
> That's fine, but more important to me is if I need to change any queries in
> my apps ;)

Nope, they should just be better.

--
  Bruce Momjian                        |  http://candle.pha.pa.us
  pgman@candle.pha.pa.us               |  (610) 359-1001
  +  If your life is a hard drive,     |  13 Roberts Road
  +  Christ can be your backup.        |  Newtown Square, Pennsylvania 19073

Re: Migration to version 7.4

From
Bruce Momjian
Date:
Nabil Sayegh wrote:
> Bruce Momjian wrote:
> >>1) Inner joins using the explicit JOIN syntax may behave differently
> >>because they are now better optimized.
> >>
> >>What exactly do you mean by 'may behave differently'?
> >
> >
> > They will be fully optimized, so they might be faster.  In pre-7.4, ANSI
> > syntax restricted the choices researched by the optimizer.
>
> That's fine, but more important to me is if I need to change any queries in
> my apps ;)

I mean they should just run better.

--
  Bruce Momjian                        |  http://candle.pha.pa.us
  pgman@candle.pha.pa.us               |  (610) 359-1001
  +  If your life is a hard drive,     |  13 Roberts Road
  +  Christ can be your backup.        |  Newtown Square, Pennsylvania 19073