Index: openacs-4/tcl/0-acs-init.tcl
===================================================================
RCS file: /usr/local/cvsroot/openacs-4/tcl/0-acs-init.tcl,v
diff -u -r1.7.2.2 -r1.7.2.3
--- openacs-4/tcl/0-acs-init.tcl	26 Sep 2015 12:58:09 -0000	1.7.2.2
+++ openacs-4/tcl/0-acs-init.tcl	1 Dec 2015 14:38:54 -0000	1.7.2.3
@@ -12,12 +12,28 @@
     # Determine, under which server we are running
     #
     set ::acs::useNaviServer [expr {[ns_info name] eq "NaviServer"}]
+
     #
-    # Handling NaviServer deprecated ns_info subcommands. 
+    # Initialize the list of known database types .  User code should use the database
+    # API routine db_known_database_types rather than reference the nsv list directly.
+    # We might change the way this is implemented later.  Each database type is
+    # represented by a list consisting of the internal name, driver name, and
+    # "pretty name" (used by the APM to list the available database engines that 
+    # one's package can choose to support).  The driver name and "pretty name" happen
+    # to be the same for Postgres and Oracle but let's not depend on that being true
+    # in all cases...
     #
+
+    set ::acs::known_database_types {
+        {oracle Oracle Oracle}
+        {postgresql PostgreSQL PostgreSQL}
+    }
+
+    #
+    # Enable / disable features depending on availability
+    #
     set ::acs::pageroot [expr {$::acs::useNaviServer ? [ns_server pagedir] : [ns_info pageroot]}]
     set ::acs::tcllib   [expr {$::acs::useNaviServer ? [ns_server tcllib] : [ns_info tcllib]}]
-    #
     set ::acs::rootdir  [file dirname [string trimright $::acs::tcllib "/"]]
     set ::acs::useNsfProc [expr {[info commands ::nsf::proc] ne ""}]
 }