Обсуждение: explicit joins vs implicit joins
Once upon a time when I taught myself sql I learned the explicit join syntax-- I have never really used the where clause to create joins. With this style of sql I have been building/maintaining a postgresql-centric web application since postgresql 7.0 and now I am learning that by writing my sql in this fashion I am constricting the planner. After reading this: http://marc.theaimsgroup.com/?l=postgresql-general&m=105551123915183&w=2 I am wondering if things are going to change in 7.4? Or should I switch to placing joins in the where clause when I can? I don't want to have to worry about my join order-- I would prefer to let the planner do its thing 95% of the time. culley
On Thu, Jun 19, 2003 at 09:52:26 +0200, culley harrelson <culley@fastmail.fm> wrote: > Once upon a time when I taught myself sql I learned the explicit join > syntax-- I have never really used the where clause to create joins. > With this style of sql I have been building/maintaining a > postgresql-centric web application since postgresql 7.0 and now I am > learning that by writing my sql in this fashion I am constricting the > planner. After reading this: > > http://marc.theaimsgroup.com/?l=postgresql-general&m=105551123915183&w=2 > > I am wondering if things are going to change in 7.4? Or should I switch > to placing joins in the where clause when I can? I don't want to have > to worry about my join order-- I would prefer to let the planner do its > thing 95% of the time. Currently using the explicit join syntax forces join order. In 7.4 it won't (unless you change a setting). So for you, 7.4 should be an improvement.
culley harrelson <culley@fastmail.fm> writes: > http://marc.theaimsgroup.com/?l=postgresql-general&m=105551123915183&w=2 > I am wondering if things are going to change in 7.4? Did you actually read the cited links? regards, tom lane
> Did you actually read the cited links? > I read the 7.3 docs then fired off an email and forgot about 7.4 docs. duh! sorry.