Megatest

	   '("avg_disk"       #f)
	   '("tags"           #f)
	   '("jobgroup"       #f)))))
    
;; tbls is ( ("tablename" ( "field1" [#f|proc1] ) ( "field2" [#f|proc2] ) .... ) )
(define (db:sync-tables tbls fromdb todb . slave-dbs)
  (mutex-lock! *db-sync-mutex*)
  (handle-exceptions
   exn
   (begin
     (debug:print 0 "EXCEPTION: database probably overloaded or unreadable in db:sync-tables.")
     (debug:print 0 " message: " ((condition-property-accessor 'exn 'message) exn))
     (print "exn=" (condition->list exn))
     (debug:print 0 " status:  " ((condition-property-accessor 'sqlite3 'status) exn))
     (print-call-chain))
   (cond
    ((not fromdb) (debug:print 3 "WARNING: db:sync-tables called with fromdb missing") -1)
    ((not todb)   (debug:print 3 "WARNING: db:sync-tables called with todb missing") -2)
    ((not (sqlite3:database? fromdb))
     (debug:print 0 "ERROR: db:sync-tables called with fromdb not a database " fromdb) -3)
    ((not (sqlite3:database? todb))
     (debug:print 0 "ERROR: db:sync-tables called with todb not a database " todb) -4)
    (else
     (let ((stmts       (make-hash-table)) ;; table-field => stmt
	   (all-stmts   '())              ;; ( ( stmt1 value1 ) ( stml2 value2 ))
	   (numrecs     (make-hash-table))
	   (start-time  (current-milliseconds))
	   (tot-count   0))
       (for-each ;; table
	(lambda (tabledat)
	  (let* ((tablename  (car tabledat))
		 (fields     (cdr tabledat))
		 (num-fields (length fields))
		 (field->num (make-hash-table))
		 (num->field (apply vector (map car fields)))
		 (full-sel   (conc "SELECT " (string-intersperse (map car fields) ",") 
				   " FROM " tablename ";"))
		 (full-ins   (conc "INSERT OR REPLACE INTO " tablename " ( " (string-intersperse (map car fields) ",") " ) "
				   " VALUES ( " (string-intersperse (make-list num-fields "?") ",") " );"))
		 (fromdat    '())
		 (todat      (make-hash-table))
		 (count      0))

	    ;; set up the field->num table
	    (for-each
	     (lambda (field)
	       (hash-table-set! field->num field count)
	       (set! count (+ count 1)))
	     fields)

	    ;; read the source table
	    (sqlite3:for-each-row
	     (lambda (a . b)
	       (set! fromdat (cons (apply vector a b) fromdat)))
	     fromdb
	     full-sel)

	    (debug:print-info 2 "found " (length fromdat) " records to sync")

	    ;; read the target table
	    (sqlite3:for-each-row
	     (lambda (a . b)
	       (hash-table-set! todat a (apply vector a b)))
	     todb
	     full-sel)

	    ;; first pass implementation, just insert all changed rows
	    (for-each 
	     (lambda (targdb)
	       (let ((stmth (sqlite3:prepare targdb full-ins)))
		 (sqlite3:with-transaction
		  targdb
		  (lambda ()
		    (for-each ;; 
		     (lambda (fromrow)
		       (let* ((a    (vector-ref fromrow 0))
			      (curr (hash-table-ref/default todat a #f))
			      (same #t))
			 (let loop ((i 0))
			   (if (or (not curr)
				   (not (equal? (vector-ref fromrow i)(vector-ref curr i))))
			       (set! same #f))
			   (if (and same
				    (< i (- num-fields 1)))
			       (loop (+ i 1))))
			 (if (not same)
			     (begin
			       (apply sqlite3:execute stmth (vector->list fromrow))
			       (hash-table-set! numrecs tablename (+ 1 (hash-table-ref/default numrecs tablename 0)))))))
		     fromdat)))
		 (sqlite3:finalize! stmth)))
	     (append (list todb) slave-dbs))))
	tbls)
       (let* ((runtime      (- (current-milliseconds) start-time))
	      (should-print (common:low-noise-print 30 "db sync" (> runtime 500)))) ;; low and high sync times treated as separate.
	 (if should-print (debug:print 0 "INFO: db sync, total run time " runtime " ms"))
	 (for-each 
	  (lambda (dat)
	    (let ((tblname (car dat))
		  (count   (cdr dat)))
	      (set! tot-count (+ tot-count count))
	      (if (> count 0)
		  (if should-print (debug:print 0 (format #f "    ~10a ~5a" tblname count))))))
	  (sort (hash-table->alist numrecs)(lambda (a b)(> (cdr a)(cdr b))))))
       tot-count)))
   (mutex-unlock! *db-sync-mutex*)))

;; options:
;;
;;  'killservers  - kills all servers
;;  'dejunk       - removes junk records
;;  'adj-testids  - move test-ids into correct ranges
;;  'old2new      - sync megatest.db records to .db/{main,1,2 ...}.db