Do you know of java-based, in-memory databases other than HSQLDB and H2?

[lbrtchx]

I need to know of any other active development in this area
..
Thanks
lbrtchx

 

[Daniel Pitts]

I need to know of any other active development in this area
.
Thanks
lbrtchx

A quick google of "java memory database" revealse
http://www.freeprogrammingresources.com/dbservers.html.
which lists a few. Try google for more info.

 

[Thomas Kellerer]

Apache Derby:

http://db.apache.org/derby

I need to know of any other active development in this area
.
Thanks
lbrtchx

 

[hiwa]

I need to know of any other active development in this area
.
Thanks
lbrtchx

Prevayler
http://www.prevayler.org/

 

[lbrtchx]

A quick google of "java memory database" revealse

http://www.freeprogrammingresources.com/dbservers.html.
which lists a few.

..
I wonder what are the few DBs listed as "java memory database",
because I had checked this link already and only gave me the ones I
know about already.
..

Try google for more info.

Hmm! Google, ... how interesting!
..

http://db.apache.org/derby

Does derby suport in-memory mode? Since when?
..
// __ http://db.apache.org/derby/faq.html#in_memory
4.8. Does Derby have a mode that causes it to run entirely in memory?
No, Derby does not support an in-memory mode, but a feature request has
been logged in JIRA as DERBY-646. When this FAQ entry was written
(e-mail address removed) list activity indicated that some work had been
done but that the feature is not actively being worked on. Check that
mail list for current status.
..
lbrtchx

 

[Narahari]

when derby is started in its embedded mode, it runs in the same JVM as
the program calling it. I belive this is some kind of in memory
usage... also there is a small demo on the derby site which shows how
to use the DB within a web browser session...

~harry

 

[lbrtchx]

when derby is started in its embedded mode, it runs in the same JVM as

the program calling it.

So?
..

I belive this is some kind of in memory
usage...

"some kind of in memory usage" will all applications have, but they
don't run -totally- in-memory
..

also there is a small demo on the derby site which shows how
to use the DB within a web browser session...

?
..
lbrthcx

 

[Lee Fesperman]

I need to know of any other active development in this area

Take a look a FirstSQL/J (see my sig); it provides both in-memory and disk mode and is
pure Java.

 

[lbrtchx]

Take a look a FirstSQL/J (see my sig); it provides both in-memory and disk mode and is
pure Java.

..
I hadn't seen a site without a search box for a long time ;-)
..
As we know, we tech monkeys tend to have very little time. Could you
send me a link to th documentation on the in-mem usage in firstsql?
..
The FAQ wasn't helpful.
..
lbrtchx

 

[Lee Fesperman]

As we know, we tech monkeys tend to have very little time. Could you
send me a link to th documentation on the in-mem usage in firstsql?

The best online description I could find is at http://www.firstsql.com/fsjbeta2.shtml.
Even better, you could take the free download of the product at
http://www.firstsql.com/download.shtml and read the regular docs on in-memory support.

 

[lbrtchx]

based on this very link, FirstSQL/J does not appear to be working
-totally- in-memory, as it is needed in a set up that could not even
have a hard drive
..
FirstSQL/J In-memory Mode
....
Except for increased performance with In-memory mode, the only
difference you will notice is the optional "mode=" startup option and
the creation of the log files and persistent .tab and .ndx files in the
Server/db directory when starting and stopping the database in memory.
..
Processing is as follows:
....
- Any changes to tables (in memory) are logged in a roll forward
journal and written to disk.
- With a controlled shutdown, the engine rewrites all changed tables &
indexes from memory back to disk in FirstSQL/J file format.
....
..
FirstSQL/J is the only commercially available 100% Java IMDB and, as
the first and most sophisticated 100% Java IMDB on the market, it can
be positioned as the leader now and for years to come.
..
I am planning to do some testing of java DBMSs (in-memory and
disk-base ones) and so far I think I will pick H2, HSQLDB, Derby, (very
probably FirstSQL/J,) PostgreSQL and Firebird
..
I hope more DBMS developers would see the benefit of in-mem modes
..
lbrtchx

 

[Lee Fesperman]

based on this very link, FirstSQL/J does not appear to be working
-totally- in-memory, as it is needed in a set up that could not even
have a hard drive

That is provided by Flash Mode. The link I gave doesn't provide detail on that mode (I
couldn't tell what you were looking for; the regular docs cover it better.) Flash Mode
is *totally* in-memory, no disk at all. For example, we've run the ORDBMS in Flash Mode
in a unsigned applet (no disk access.)

I hope more DBMS developers would see the benefit of in-mem modes
.

The cost of memory continues to drop, and the standard amount of memory on systems
continue to rise, even on mobile devices. 64-bit systems are becoming more prevalent. We
see in-memory databases as a growth area. And, then there are the significant
performance benefits...