If I'm correct we wrote about it on the seaside book
http://book.seaside.st
Le 27/9/15 20:23, Adam a écrit :
Hello,
thank You for great hints. I will look at this.
Have a nice day,
Adam.
Dne Ne 27. září 2015 19:16:10, [email protected] napsal(a):
Adam,
SandstoneDb may be of interest to you:
http://www.smalltalkhub.com/#!/~gnaritas/SandstoneDb
"SandstoneDb is a lightweight Prevayler style embedded object database with
an ActiveRecord API that doesn't require a command pattern and works for
small apps that a single Squeak image can handle. The idea is to make a
Squeak image durable and crash proof and suitable for use in small office
applications.
Data is kept in ram for speed and on disk for safety. All data is reloaded
from disk on image startup.
Since we're dealing with live objects in memory, concurrency is handled via
optional record level critical sections rather than optimistic locking and
commit failures. It's up to the developer to use critical sections at the
appropriate points by using the critical method on the record.
Saves are atomic for an ActiveRecord and all its non ActiveRecord children,
for example, an order and its items. There is no atomic save across
multiple ActiveRecords. A record is a cluster of objects that are stored in
a single file together.
After installing SandstoneDb make sure to restart your image before
attempting to use it or running the tests."
Fuel may also have something in stock:
https://ci.inria.fr/pharo-contribution/view/Books/job/EnterprisePharoBook/la
stSuccessfulBuild/artifact/book-result/Fuel/Fuel.pdf
I also use Mapless
http://sebastianconcept.github.io/Mapless/
HTH
Phil
On Sun, Sep 27, 2015 at 6:47 PM, Adam <[email protected]> wrote:
Hello,
I was wondering if it is possible for Pharo to load lots of data and query
them without using external DB, just using object memory. Well, someting
like
GemStone/S, but not so sophisticated.
I did some research so here is details what I found. I would appreciate if
someone can tell me if any points of this agenda can be allready done or
need
to be programmed, or if this whole idea is waste of time and it is better
to
use external DB.
1) Object memory limit: Current object memory of Pharo is limited to 4GB.
Free
version of GemStone/S is also limited to 4GB, so I would rather stick with
Pharo until I reach this level. And in the future this limit grow due to
64bit
version of VM.
2) Saving to disk: Is it possible to save object or group of objects to
disk
and ensure consistency? With some transaction mechanism and transaction
log?
3) RAM limit: Is it possible to delete objects from memory, move them to
the
disk and not break its connections to other objects? For example by
redirecting object internal ID to some kind of hollow object, that will
renew
receiver of message from disk if necessary... This approach can also
possibly
split object memory into more "remote" sources.
4) Indexing: What optimalization for searching current collections in
Pharo
do? For example: how to store instances of City if I would like to search
through it by name and also by its postal code? Is there some library for
creating fulltext search (maybe Spotter uses that - I did not study it
yet).
Have a nice day, and thanks for any answer.
Adam
