Re: Join questions

Informix uses internal optimizer to determine optimal join (loop or hash join). You can force a kind of join only with optimizer directives... "Rich" <rleonard@rocketmail.com> wrote in message news:gCHab.15275$uJ2.5665@fe3.columbus.rr.com... > I have a couple fairly basic join questions I am hoping someone can answer. > I am familiar with other DB's but am new to Informix. Here are two queries > which I am trying to understand... > > 1) select ... from table1, table2, outer table3, outer table4 where ... > > Is the outer join a left or right outer join? Since there is no "on" > clause, how does Informix join the tables? > > 2) select ... from table1, inner loop join table2 on <condition> inner loop > join table3 on <condition> left outer join table4 on <condition> left outer > join table3 on <condition> > > What is the difference between an inner join and an inner loop join? How do > the inner loop joins and left outer joins interact? > > Thanks for any help you can give! > Rich > >