Support for ANSI join syntax differs between Adaptive Server Enterprise, SAP SQL Anywhere, and SAP Sybase IQ.
SAP Sybase IQ does not currently support subqueries in the ON clause.
Adaptive Server Enterprise and SAP SQL Anywhere support subqueries in the ON clause.
A CONTAINS condition in the FROM clause in queries using ANSI join syntax is supported but may have suboptimal performance. Using Outer Joins for CONTAINS in the FROM clause should only be used if the “score” column from each of the CONTAINS clauses is required. Otherwise CONTAINS should be moved to an ON condition or WHERE clause.
SAP SQL Anywhere and SAP Sybase IQ support FULL OUTER JOIN.
Adaptive Server Enterprise does not support FULL OUTER JOIN.