Обсуждение: Migration to version 7.4
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
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
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
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
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