Controls whether queries with an ambiguous syntax for multi-table joins are allowed or are reported as an error.
Option can be set at the database (PUBLIC) or user level. When set at the database level, the value becomes the default for any new user, but has no impact on existing users. When set at the user level, overrides the PUBLIC value for that user only. No system privilege is required to set option for self. System privilege is required to set at database level or at user level for any user other than self.
Requires the SET ANY PUBLIC OPTION system privilege to set this option. Can be set temporary for an individual connection or for the PUBLIC role. Takes effect immediately.
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.
This 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 EXTENDED_JOIN_SYNTAX 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 )