ADDED   mockup-cached-writes.scm
Index: mockup-cached-writes.scm
==================================================================
--- /dev/null
+++ mockup-cached-writes.scm
@@ -0,0 +1,22 @@
+
+
+(define (make-cached-writer the-db)
+  (let ((db    the-db)
+	(queue '()))
+    (lambda (cacheable . qry-params)
+      (if cacheable
+	  (set! queue (cons qry-params queue))
+	  (begin
+	    (print "Starting transaction")
+	    (for-each
+	     (lambda (queue-item)
+	       (print "WRITE to " db ": " queue-item))
+	     (reverse queue))
+	    (print "End transaction")
+	    (print "READ from " db ": " qry-params))))))
+
+(define a (make-cached-writer "the db"))
+(a #t "insert abc")
+(a #t "insert def")
+(a #t "insert hij")
+(a #f "select foo")