Natan <nvivo@mandic.com.br> writes:
> Can anyone tell me if there is any difference between these two commands:
> select * from table1, table2 where table1.id = table2.id
> and
> select * from table1 inner join table 2 on table1.id = table2.id
Nope.
> I checked the query plan for both and they appear exactly the same. But
> in this case, i am working with only two tables in a very simple
> join.... What i would like to know is: in a production environment with
> lots of joins and where clauses, does it make any difference to write in
> one form or in the other, or the joins are like shortcuts to the first form?
With more than two tables, it *can* make a difference. If using 7.4,
see
http://www.postgresql.org/docs/7.4/static/explicit-joins.html
Earlier versions were a bit different --- make the obvious change in
the URL to see the corresponding docs for your version.
regards, tom lane