There are a number of notes From Oracle Support site on issues with ANSI join syntax with workarounds recommeding to use the oracle syntax.
Bug 5188321 wrong results (no rows) OR ORA-1445 from ANSI outer join
Versions affected: Versions >= 126.96.36.199 but < 11
Wrong results or an ORA-1445 can be returned with a query involving a
very large select list count when ANSI OUTER JOIN syntax is used.
Use native oracle outer join syntax
reduce the select list count.
Bug 5368296 ANSI join SQL may not report ORA-918 for ambiguous column
Versions affected: Versions < 11
Note: This fix introduces the problem described in bug 7318276
One off fixes for that bug address the issue here also.
ORA-918 is not reported for an ambiguous column in a query
involving an ANSI join of more than 2 tables/objects.
-- 2 table join, returns ORA-918
FROM emp a JOIN emp b on a.empno = b.empno;
-- 3 table join does not report ORA-918 when it should ...
FROM emp a JOIN emp b on a.empno = b.empno
JOIN emp c on a.empno = c.empno;
Bug 7670135 Long parse time compiling ANSI join
Versions affected: Versions BELOW 11.2
A query having ANSI join(s) may take noticeable time during query compilation,
especially if the query includes an NVL() function.
Use ORACLE join instead of ANSI join
From the Oracle Press - Oracle OCP 11g all in one exam guide
And from asktom (who is non committal)
Historically there have been bugs related to ANSI syntax, in fact even the
10.2.0.4 projected issues list includes 10 bugs/issues related to ANSI syntax.
In the past I've encountered some of these bugs myself, and have continued to use
and advocate the "traditional" Oracle style.
I'd like to know if you feel that the implementation of ANSI syntax is now equally
robust compared to the traditional syntax.
Followup February 19, 2008 - 5pm Central time zone:
unfortunately, there are bugs in non-ansi joins too, probably more than 10 in fact.
I personally do not use the new syntax (except in the rare case of a full outer join,
a truly rare beast to encounter). I have no comment on it really.
See also earlier question on same topic
Different between Oracle's plus notation over ansi join notation?
I also found this statement in a document but no reference as to where it came from
"Starting with Oracle 9i, Oracle recommends that SQL developers use the ANSI join syntax instead of the Oracle proprietary (+) syntax. There are several reasons for this recommendation, including:
â€˘ Easier to segregate and read (without mixing up join versus restriction code)
â€˘ Easier to construct join code correctly (especially in the case of â€śouterâ€ť joins)
â€˘ Portable syntax will work on all other ANSI compliant databases, such as MS SQL Server, DB2, MySQL, PostgreSQL, et al
â€˘ Since itâ€™s the universally accepted standard, itâ€™s the general target for all future database and third party vendorsâ€™ tools
â€˘ The proprietary Oracle outer-join (+) syntax can only be used in one direction at a time, it cannot perform a full outer join
â€˘ Plus these additional limitations from the Oracle documentation:
o The (+) operator can be applied only to a column, not to an arbitrary expression. However, an arbitrary expression can contain one or more columns marked with the (+) operator.
o A condition containing the (+) operator cannot be combined with another condition using the OR logical operator.
o A condition cannot use the IN comparison condition to compare a column marked with the (+) operator with an expression.
o A condition cannot compare any column marked with the (+) operator with a sub-query."
Thus itâ€™s time to embrace the ANSI join syntax â€“ and move into the 21st century