explicit joins vs implicit joins

Started by culley harrelsonalmost 23 years ago4 messagesgeneral
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#1culley harrelson
culley@fastmail.fm

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

#2Bruno Wolff III
bruno@wolff.to
In reply to: culley harrelson (#1)
Re: explicit joins vs implicit joins

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&amp;m=105551123915183&amp;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.

#3Tom Lane
tgl@sss.pgh.pa.us
In reply to: culley harrelson (#1)
Re: explicit joins vs implicit joins

culley harrelson <culley@fastmail.fm> writes:

http://marc.theaimsgroup.com/?l=postgresql-general&amp;m=105551123915183&amp;w=2
I am wondering if things are going to change in 7.4?

Did you actually read the cited links?

regards, tom lane

#4culley harrelson
culley@fastmail.fm
In reply to: Tom Lane (#3)
Re: explicit joins vs implicit joins

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.