[thelist] SQL question

Carl J Meyer cjmeyer at npcc.net
Wed Dec 11 14:09:00 CST 2002

Well, that could explain why I learned the old-style syntax, as I
learned SQL on Oracle.  These days I use mostly PostgreSQL, which
supports both join syntaxes.

It appears that at least in Postgres there is a performance
implication.  According to the docs


if you use "old-style" join syntax, the Pg query planner makes its own
decision on what order to perform the joins in, whereas if you use
new-style syntax you are specifying the join order.  So using new-style
syntax slightly reduces the time required for Postgres to plan the query
(negligible for only a few tables, but possibly serious if many tables
are involved).

Don't know whether this is true for any other DBs...



On Wed, 2002-12-11 at 07:28, Luther, Ron wrote:
> Hi Carl,
> I've read through the other replies so far and I haven't seen anyone
> comment yet on your question of whether this could be db specific.
> I usually play in Oracle.  I don't use the JOIN keywords either.  I've got
> the 'Oracle - The Complete Reference' book at my desk ... and thumbing
> through and checking the index under 'JOIN' I don't see any examples that
> use the JOIN keywords.
> Now, it's a big book - I may have missed them - but unless someone else
> chimes in - it's looking to me like they aren't generally used with Oracle.
> RonL.
> -----Original Message-----
> From: Carl J Meyer [mailto:cjmeyer at npcc.net]
> I've used SQL for years in DB/web applications, and never have I ever
> used any of the JOIN keywords (INNER,OUTER,LEFT,RIGHT,JOIN,etc).
> --
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