Controls whether queries with an ambiguous syntax for multi-table joins are allowed, or reported as an error.
ON, OFF
ON
This option reports a syntax error for those queries containing outer joins that have ambiguous syntax due to the presence of duplicate correlation names on a null-supplying table.
The following join clause illustrates the kind of query that is reported where C1 is a condition.
( R left outer join T , T join S on ( C1 ) )
If the EXTENDED_JOIN_SYNTAX option is set to ON, this query is interpreted as follows, where C1 and C2 are conditions:
( R left outer join T on ( C1 ) ) join S on ( C2 )
