extended_join_syntax option

Controls whether queries with duplicate correlation names syntax for multi-table joins are allowed, or reported as an error.

Allowed values

On, Off

Default

Scope

	PUBLIC role	For current user	For other users
Allowed to set permanently?	Yes, with SET ANY PUBLIC OPTION	Yes	Yes, with SET ANY PUBLIC OPTION
Allowed to set temporarily?	Yes, with SET ANY PUBLIC OPTION	Yes (current connection only)	No

Remarks

If this option is set to On, then the database server allows duplicate correlation names to be used in the null-supplying side of outer joins. All tables or views specified with the same correlation name are interpreted as the same instance of the table or view.

The following FROM clause illustrates the SQL Anywhere interpretation of a join using duplicate correlation names where C1 and C2 are search conditions:

( R left outer join T on ( C1 ), T  join S on ( C2 ) )

If the option is set to On, this join is interpreted as follows:

( R left outer join T on ( C1 ) ) join S on ( C2 )

If the option is set to Off, SQLCODE -137 is generated.

Note To see the result of eliminating duplicate correlation names, you can view the rewritten statement using the REWRITE function with the second argument set to ANSI.