Add PostgreSQL details

doc/db-backend.txt

@@ -55,6 +55,19 @@ The table structure should be similar to this (for MySQL):
      KEY firstname (firstname,lastname)
    );
 
+and similar to this for PostgreSQL:
+CREATE TABLE "address" (
+   "owner" varchar(128) NOT NULL,
+   "nickname" varchar(16) NOT NULL,
+   "firstname" varchar(128) NOT NULL,
+   "lastname" varchar(128) NOT NULL,
+   "email" varchar(128) NOT NULL,
+   "label" varchar(255) NOT NULL,
+   CONSTRAINT "address_pkey" PRIMARY KEY ("nickname", "owner")
+);
+CREATE  UNIQUE INDEX "address_firstname_key" ON "address"
+   ("firstname", "lastname");
+
 
 Next, edit your configuration so that the address book DSN (Data Source
 Name) is specified, this can be done using either conf.pl or via the
@@ -82,6 +95,14 @@ The table structure should be similar to this (for MySQL):
     PRIMARY KEY (user,prefkey)
   );
 
+and for PostgreSQL:
+CREATE TABLE "userprefs" (
+   "user" varchar(128) NOT NULL,
+   "prefkey" varchar(64) NOT NULL,
+   "prefval" text,
+   CONSTRAINT "userprefs_pkey" PRIMARY KEY ("prefkey", "user")
+);
+
 Next, edit your configuration so that the preferences DSN (Data Source
 Name) is specified, this can be done using either conf.pl or via the
 administration plugin. The DSN should look something like: