Index: dbfile.scm
==================================================================
--- dbfile.scm
+++ dbfile.scm
@@ -191,17 +191,23 @@
 (define (dbfile:run-id->path apath run-id)
   (conc apath"/"(dbfile:run-id->dbname run-id)))
 
 (define (db:dbname->path apath dbname)
   (conc apath"/"dbname))
+
+(define num-run-dbs (make-parameter 2))
+
+(define (dbfile:run-id->dbnum run-id)
+  (cond
+   ((number? run-id)
+    (modulo run-id (num-run-dbs)))
+   ((not run-id) "main")   ;; 0 or main?
+   (else run-id)))
 
 ;; POTENTIAL BUG: this implementation could produce a db file if run-id is neither #f or a number
 (define (dbfile:run-id->dbname run-id)
-  (cond
-   ((number? run-id) (conc ".megatest/" (modulo run-id 100) ".db"))
-   ((not run-id)     (conc ".megatest/main.db"))
-   (else             run-id)))
+  (conc ".megatest/"(dbfile:run-id->dbnum run-id)".db"))
 
 ;; Make the dbstruct, setup up auxillary db's and call for main db at least once
 ;;
 ;; called in http-transport and replicated in rmt.scm for *local* access. 
 ;;
@@ -241,12 +247,16 @@
 	(begin
 	  (stack-pop! (dbr:subdb-dbstack subdb))))))
 
 ;; return a previously opened db handle to the stack of available handles
 (define (dbfile:add-dbdat dbstruct run-id dbdat)
-  (let* ((subdb (dbfile:get-subdb dbstruct run-id)))
-    (stack-push! (dbr:subdb-dbstack subdb) dbdat)
+  (let* ((subdb (dbfile:get-subdb dbstruct run-id))
+	 (dbstk (dbr:subdb-dbstack subdb))
+	 (count (stack-count dbstk)))
+    (if (> count 15)
+	(dbfile:print-err "WARNING: stack for "run-id".db is large."))
+    (stack-push! dbstk dbdat)
     dbdat))
 
 ;; set up a subdb
 ;;
 (define (dbfile:init-subdb dbstruct run-id init-proc)
@@ -1012,12 +1022,13 @@
 ;; create a dropping near the db file in a qif dir
 ;; use count of such files to gate queries (queries in flight)
 ;;
 (define (dbfile:wait-for-qif fname run-id params)
   (let* ((thedir  (pathname-directory fname))
-	 (destdir (conc thedir"/qif-"run-id))
-	 (uniqn   (get-area-path-signature (conc (or run-id "main") params)))
+	 (dbnum   (dbfile:run-id->dbnum run-id))
+	 (destdir (conc thedir"/qif-"dbnum))
+	 (uniqn   (get-area-path-signature (conc dbnum params)))
 	 (crumbn  (conc destdir"/"(current-seconds)"-"uniqn"."(current-process-id))))
     (if (not (file-exists? destdir))(create-directory (conc destdir"/attic") #t))
     (let loop ((count 0))
       (let* ((currlks (glob (conc destdir"/*")))
 	     (numqrys (length currlks))