CachedIoAdapter, as its name suggests, caches data for io access. It's very similar as operating system disk cache, which hold buffers for io operation. CachedIoAdapter would make sense for some cases like bulk operations, or no disk cache is available. Poleposition result shows that it speeds up 20%~90% on some circuits. You may take a try to see whether CachedIoAdapter fits your case. Following code shows how to use CachedIoAdapter:
delegateAdapter = new RandomAccessFileAdapter();
Db4o.configure().io(new CachedIoAdapter(delegateAdapter));
or
Db4o.configure().io(new CachedIoAdapter(delegateAdapter, 1024, 32)); where 1024 is the size of page, and 32 is the total count of pages, meaning it will cache at most 32K bytes data in memory.
Cheers!
Welcome to the February newsletter! Version 6.1 Makes db4o Even More ScalableProduct Roadmap 2007 DraftedGerman Viscuso Appointed to Host db4o CommunityNew dOCL License Well Received
K U D O O F T H E M O N T H
"I have been using db4o for .Net for about a year and a half, and I
have to tell you that you are doing yourself a disservice if you have
not tried it ... db4o can save you about 50% of your development time.
And that is a conservative estimate."
--Thomas Jaeger, 1/1/2007
A R T I C L E S
-- VERSION 6.1 MAKES db4o EVEN MORE SCALABLE --
Building on db4o v6.0's foundation for a more scalable
client/server version, Version 6.1 now brings batching of asynchronized
messages, a feature that significantly enhances performance by a factor
of 15-20x, for instance, when inserting or deleting a large number of
objects.
V6.1's client side batching queues up all actions within
one transaction and sends them to the server in a si ...
Read the rest of entry »
Currently there is a poll on http://www.java.net
"What one feature would you most like to see in JDK 7"
Closures are one possible choice. Closures would be soooo niiiiiiiice. Here is why:
List cats = database.query( { Cat cat => cat.getName().equals("Wolke") } );
Can Native Queries be more beautiful?
This is a cry to the db4o community:
Please vote for closures!
Some further links on closures:
http://www.javac.info/closures-v04.html
http://www.bejug.org/confluenceBeJUG/display/PARLEYS/Closures+for+Java
http://gafter.blogspot.com/2006/12/closures-talk-and-spec-update.html