[cl-prevalence-devel] cl-prevalence speed issues

[Gabor Vitez]

Hi,

I just started to toy around with cl-prevalence; however I found strange
speed issues:

loading a database from transaction log is way faster than loading it from
snapshot.

I modified one of the test scripts from the cl-prevalence distribution:

(require 'asdf)
(require 'cl-prevalence)
(in-package :cl-prevalence)
(defclass numbers ()
  ((numbers-list :accessor get-numbers-list :initform nil))
    (:documentation "Object to hold our list of numbers"))
(defun tx-create-numbers-root (system)
      "Transaction function to create a numbers instance as a root object"
        (setf (get-root-object system :numbers) (make-instance 'numbers)))
(defun tx-add-number (system number)
  "Transaction function to add a number to the numbers list"
  (let ((numbers (get-root-object system :numbers)))
    (push number (get-numbers-list numbers))))
(defparameter *system-location* (pathname "/tmp/demo1-prevalence-system/")
  "Filesystem location of the prevalence system")
(defvar *system* (time (make-prevalence-system *system-location*)) )
(execute *system* (make-transaction 'tx-create-numbers-root))
(time (dotimes (i 100000) (execute *system* (make-transaction 'tx-add-number
i)))        )
;(time (snapshot *system*))
(close-open-streams *system*)


I use this script to create a database; later to load it; then to snapshot
it and load it again (uncommenting the appropriate parts between the runs).

Creating and snapshotting is fast; however loading from snapshot is slow.
Times:
creating: 19.89 seconds
loading from transaction log: 53.942 seconds   < this is good
snapshotting: 5.297 seconds
loading from snapshot: 182.713 seconds          < this is strange
snapshotting again: 1.165 seconds

Any ideas what this strangeness can be?


    Gabor
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