[elephant-cvs] CVS update: elephant/TUTORIAL

[blee at common-lisp.net]

Update of /project/elephant/cvsroot/elephant
In directory common-lisp.net:/tmp/cvs-serv30393

Modified Files:
	TUTORIAL 
Log Message:
comments on initforms and transactions

Date: Thu Sep  2 16:39:12 2004
Author: blee

Index: elephant/TUTORIAL
diff -u elephant/TUTORIAL:1.4 elephant/TUTORIAL:1.5
--- elephant/TUTORIAL:1.4	Sun Aug 29 22:35:37 2004
+++ elephant/TUTORIAL	Thu Sep  2 16:39:12 2004
@@ -250,6 +250,11 @@
 you're concerned, cache values.  (In the future we will
 provide automatic value caching.)
 
+Finally, if you for some reason make an instance with a
+specified OID which already exists in the database, initargs
+take precedence over values in the database, which take
+precedences over initforms.
+
 ------------
 Transactions
 ------------
@@ -388,3 +393,21 @@
 The serializer is definitely fast on fixnums, strings, and
 persistent things.  It is fairly fast but consing with
 floats and doubles.  YMMV with other values.
+
+Using *auto-commit* and not "with-transactions" is a great
+way to have a huge number of transactions.  You'll find that
+
+(dotimes (i 1000) (add-to-root "key" "value"))
+
+is way slower than
+
+(let ((*auto-commit* nil))
+ (with-transaction ()
+  (dotimes (i 1000) (add-to-root "key" "value"))))
+
+since there's only 1 transaction in the latter.
+
+Use the persistent classes and collections; if you're using
+transactions correctly they should be much faster.
+
+If you don't need transactions you can turn them off.