The Free On-line Dictionary of Computing (30 December 2018):

SQL3

    A draft standard for another
   extension of SQL.  The latest SQL3 Working Draft addresses
   the requirement for objects and "object identifiers" in SQL
   and also specifies supporting features such as
   encapsulation, subtypes, inheritance, and
   polymorphism.

   In the USA, SQL3 is being processed as both an ANSI Domestic
   ("D") project and as an ISO project.  It is expected to be
   complete in 1998.

   November 1992 paper
   (ftp://speckle.ncsl.nist.gov/isowg3/dbl/BASEdocs/sql3overview.txt).

   Working draft (ftp://gatekeeper.dec.com/pub/standards/sql/).

   [ISO/IEC SQL Revision.  ISO-ANSI Working Draft Database
   Language SQL (SQL3), Jim Melton - Editor, document ISO/IEC
   JTC1/SC21 N6931, ANSI, July 1992].

   [Current Status?]

   (2002-04-21)