This program (known as UCB/INGRES) was written at the University of
California between 1973 and 1978.  It is public domain code, and you
are free to make any modifications.  Moreover, it is unsupported; there
is no person or organization who can help you with bugs or problems.
However, this code has had a number of bugs fixed which were in the
original Berkeley distribution version. It contains support for
concurrent access to its databases from multiple users (which can
be built optionally), and so is usable where a database must be
constructed which may be simultaneously accessed by several people.

UCB/INGRES should be carefully distinguished from the commercial
version of INGRES available both from Sun Microsystems, Inc. and
Relational Technology, Inc.  The commercial version is supported, has a
great deal more function and has substantially higher performance on
most interactions.