Persistence in VW

No, we have our own db mapping framework at the core of our application. With GLORP there is quite a bit of flexibility as far as your mapping is concerned, but it has relational db as the store, so you would need to be familiar with it somewhat. Other options are gemstone, boss files or xml :)

Cheers!

-Boris
(Sent from a BlackBerry)

----- Original Message -----
From: [hidden email] <[hidden email]>
To: [hidden email] <[hidden email]>
Sent: Tue Dec 11 22:14:01 2007
Subject: Re: [Seaside] Persistence in VW


Hello Boris and Michael!

Thanks for your advises. I want to ask for a few more questions:

I have a lot of inheritance: Template - Flow template; different kind of
rows; reconciliated report. How will they work?

Currently i am storing all data in class side dictionaries and a lot of
binding was done with dictionaries too. Can i keep them or i should remake
bindings for the relation needs through ids.

Should i keep my dictionaries or i should make afinders un database in place
of them?

And main problem: I have a report object which stores a values in hash where
the row code (3 letter) is a key and money amount is a value. How can i
store this in db using glorp? I dont have special class for it, so how to do
mapping? Can u show me example?

Boris are you using ActiveRecord and GLORP too?

Oleg
--
View this message in context: http://www.nabble.com/Persistence-in-VW-tp14283675p14289650.html
Sent from the Squeak - Seaside mailing list archive at Nabble.com.

_______________________________________________
seaside mailing list
[hidden email]
http://lists.squeakfoundation.org/cgi-bin/mailman/listinfo/seaside

Boris Popov-2 wrote

No, we have our own db mapping framework at the core of our application. With GLORP there is quite a bit of flexibility as far as your mapping is concerned, but it has relational db as the store, so you would need to be familiar with it somewhat. Other options are gemstone, boss files or xml :)

Cheers!

-Boris
(Sent from a BlackBerry)

----- Original Message -----
From: seaside-bounces@lists.squeakfoundation.org <seaside-bounces@lists.squeakfoundation.org>
To: seaside@lists.squeakfoundation.org <seaside@lists.squeakfoundation.org>
Sent: Tue Dec 11 22:14:01 2007
Subject: Re: [Seaside] Persistence in VW


Hello Boris and Michael!

Thanks for your advises. I want to ask for a few more questions:

I have a lot of inheritance: Template - Flow template; different kind of
rows; reconciliated report. How will they work?

Currently i am storing all data in class side dictionaries and a lot of
binding was done with dictionaries too. Can i keep them or i should remake
bindings for the relation needs through ids.

Should i keep my dictionaries or i should make afinders un database in place
of them?

And main problem: I have a report object which stores a values in hash where
the row code (3 letter) is a key and money amount is a value. How can i
store this in db using glorp? I dont have special class for it, so how to do
mapping? Can u show me example?

Boris are you using ActiveRecord and GLORP too?

Oleg
--
View this message in context: http://www.nabble.com/Persistence-in-VW-tp14283675p14289650.html
Sent from the Squeak - Seaside mailing list archive at Nabble.com.

_______________________________________________
seaside mailing list
seaside@lists.squeakfoundation.org
http://lists.squeakfoundation.org/cgi-bin/mailman/listinfo/seaside

_______________________________________________
seaside mailing list
seaside@lists.squeakfoundation.org
http://lists.squeakfoundation.org/cgi-bin/mailman/listinfo/seaside

Boris!

What about my other questions (inheritance, integer storage)? Can you
recommend me something?

Oleg



Boris Popov-2 wrote:
>
> No, we have our own db mapping framework at the core of our application.
> With GLORP there is quite a bit of flexibility as far as your mapping is
> concerned, but it has relational db as the store, so you would need to be
> familiar with it somewhat. Other options are gemstone, boss files or xml
> :)
>
> Cheers!
>
> -Boris
> (Sent from a BlackBerry)
>
> ----- Original Message -----
> From: [hidden email]
> <[hidden email]>
> To: [hidden email]
> <[hidden email]>
> Sent: Tue Dec 11 22:14:01 2007
> Subject: Re: [Seaside] Persistence in VW
>
>
> Hello Boris and Michael!
>
> Thanks for your advises. I want to ask for a few more questions:
>
> I have a lot of inheritance: Template - Flow template; different kind of
> rows; reconciliated report. How will they work?
>
> Currently i am storing all data in class side dictionaries and a lot of
> binding was done with dictionaries too. Can i keep them or i should remake
> bindings for the relation needs through ids.
>
> Should i keep my dictionaries or i should make afinders un database in
> place
> of them?
>
> And main problem: I have a report object which stores a values in hash
> where
> the row code (3 letter) is a key and money amount is a value. How can i
> store this in db using glorp? I dont have special class for it, so how to
> do
> mapping? Can u show me example?
>
> Boris are you using ActiveRecord and GLORP too?
>
> Oleg
> --
> View this message in context:
> http://www.nabble.com/Persistence-in-VW-tp14283675p14289650.html
> Sent from the Squeak - Seaside mailing list archive at Nabble.com.
>
> _______________________________________________
> seaside mailing list
> [hidden email]
> http://lists.squeakfoundation.org/cgi-bin/mailman/listinfo/seaside
>
> _______________________________________________
> seaside mailing list
> [hidden email]
> http://lists.squeakfoundation.org/cgi-bin/mailman/listinfo/seaside
>
>

--
View this message in context: http://www.nabble.com/Persistence-in-VW-tp14283675p14292647.html
Sent from the Squeak - Seaside mailing list archive at Nabble.com.

_______________________________________________
seaside mailing list
[hidden email]
http://lists.squeakfoundation.org/cgi-bin/mailman/listinfo/seaside

Alan Knight-2 wrote

Inheritance is always rather tricky against a relational database, because the concept really isn't there, so you have to map it into some compromise, trading off space, query time, and flexibility. Glorp supports two different strategies for this, which we call horizontal and filtered. Filtered inheritance means all instances are stored in one bit table, and there's a field which indicates which type this row represents. This is efficient to query, but wastes spaces. Horizontal is where each subclass is represented by an entirely separate table. This is more likely if you're trying to impose an inheritance hierarchy on an existing database, and minimizes storage, but makes querying more complex. Some kinds of queries can be inefficient. You'd want to look at the TypeResolver class and its subclasses. In the Glorp tests, GlorpInheritanceDescriptorSystem has some examples.

By comparison, storing integers and dictionaries is pretty easy :-) If you want both key and value to be simple types, then you need a table somewhere to store them. If the value is an object, you can either have the key be part of the value's table, or in a link table. GlorpDictionaryMappingTest and GlorpEncyclopediaDescriptorSystem have examples.

Neither of those things is likely to work automatically with the GlorpActiveRecord code, you'll likely have to write out the mappings. But part of the point of the way GlorpActiveRecord is done is that you can let the parts that are easy get built automatically and only have to specify the tricky parts.

Thank you Alan!

I will look at this classes. I need a little help with ActiveRecord? Can you
show me how to use it? I understand that i should inherit all my models from
AR class, but what next. Should i execute something in workspace? And how to
attach session  to active record?





Alan Knight-2 wrote:
>
> Inheritance is always rather tricky against a relational database, because
> the concept really isn't there, so you have to map it into some
> compromise, trading off space, query time, and flexibility. Glorp supports
> two different strategies for this, which we call horizontal and filtered.
> Filtered inheritance means all instances are stored in one bit table, and
> there's a field which indicates which type this row represents. This is
> efficient to query, but wastes spaces. Horizontal is where each subclass
> is represented by an entirely separate table. This is more likely if
> you're trying to impose an inheritance hierarchy on an existing database,
> and minimizes storage, but makes querying more complex. Some kinds of
> queries can be inefficient. You'd want to look at the TypeResolver class
> and its subclasses. In the Glorp tests, GlorpInheritanceDescriptorSystem
> has some examples.
>
> By comparison, storing integers and dictionaries is pretty easy :-) If you
> want both key and value to be simple types, then you need a table
> somewhere to store them. If the value is an object, you can either have
> the key be part of the value's table, or in a link table.
> GlorpDictionaryMappingTest and GlorpEncyclopediaDescriptorSystem have
> examples.
>
> Neither of those things is likely to work automatically with the
> GlorpActiveRecord code, you'll likely have to write out the mappings. But
> part of the point of the way GlorpActiveRecord is done is that you can let
> the parts that are easy get built automatically and only have to specify
> the tricky parts.
>
>
>

--
View this message in context: http://www.nabble.com/Persistence-in-VW-tp14283675p14300415.html
Sent from the Squeak - Seaside mailing list archive at Nabble.com.

_______________________________________________
seaside mailing list
[hidden email]
http://lists.squeakfoundation.org/cgi-bin/mailman/listinfo/seaside

Alan Knight-2 wrote

Sure. It should (hopefully) be fairly easy to use, although if you're completely new to Glorp it probably can get interesting.

Subclass your classes from ActiveRecord. Then use ActiveRecordDescriptorSystem, or your own subclass of it, as the system, and log in. If you use the main class, it'll try to use all subclasses of ActiveRecord. If you make your own subclass you can implement #defaultRootClass to make it just be subclasses of your own abstract superclass (which it expects to be a subclass of ActiveRecord).

If you've named your classes according to the generally Ruby on Rails-ish conventions, which is to say that the Customer class corresponds to the CUSTOMERS table (or the CUSTOMER table, it's not all that fussy), then it should try to generate descriptors for that automatically. It'll do a good deal better if your foreign key fields are identified as such in the database. For parts that it doesn't get right, or at all, you can implement the normal Glorp methods like #descriptorForMyClassName:, but you should only have to give it the information for the mappings it didn't get right in the first place.

There are some simple examples in the GlorpActiveRecordTests package. Once it's mapped, then you can do a number of things by sending messages to the objects or their classes that would typically require you to use the Glorp session. e.g. aClass findWhere:, anObject save, etc.

At 12:57 PM 12/12/2007, Oleg Richards wrote:

>Thank you Alan!
>
>I will look at this classes. I need a little help with ActiveRecord? Can you
>show me how to use it? I understand that i should inherit all my models from
>AR class, but what next. Should i execute something in workspace? And how to
>attach session  to active record?
>
>
>
>
>
>Alan Knight-2 wrote:
>>
>> Inheritance is always rather tricky against a relational database, because
>> the concept really isn't there, so you have to map it into some
>> compromise, trading off space, query time, and flexibility. Glorp supports
>> two different strategies for this, which we call horizontal and filtered.
>> Filtered inheritance means all instances are stored in one bit table, and
>> there's a field which indicates which type this row represents. This is
>> efficient to query, but wastes spaces. Horizontal is where each subclass
>> is represented by an entirely separate table. This is more likely if
>> you're trying to impose an inheritance hierarchy on an existing database,
>> and minimizes storage, but makes querying more complex. Some kinds of
>> queries can be inefficient. You'd want to look at the TypeResolver class
>> and its subclasses. In the Glorp tests, GlorpInheritanceDescriptorSystem
>> has some examples.
>>
>> By comparison, storing integers and dictionaries is pretty easy :-) If you
>> want both key and value to be simple types, then you need a table
>> somewhere to store them. If the value is an object, you can either have
>> the key be part of the value's table, or in a link table.
>> GlorpDictionaryMappingTest and GlorpEncyclopediaDescriptorSystem have
>> examples.
>>
>> Neither of those things is likely to work automatically with the
>> GlorpActiveRecord code, you'll likely have to write out the mappings. But
>> part of the point of the way GlorpActiveRecord is done is that you can let
>> the parts that are easy get built automatically and only have to specify
>> the tricky parts.
>>
>>
>>
>
>--
>View this message in context: http://www.nabble.com/Persistence-in-VW-tp14283675p14300415.html
>Sent from the Squeak - Seaside mailing list archive at Nabble.com.
>
>_______________________________________________
>seaside mailing list
>seaside@lists.squeakfoundation.org
>http://lists.squeakfoundation.org/cgi-bin/mailman/listinfo/seaside

--
Alan Knight [|], Cincom Smalltalk Development
knight@acm.org
aknight@cincom.com
http://www.cincom.com/smalltalk

_______________________________________________
seaside mailing list
seaside@lists.squeakfoundation.org
http://lists.squeakfoundation.org/cgi-bin/mailman/listinfo/seaside

If you guys using VW really dont have a viable OODBMS persistence option
to offer perhaps you might consider porting Magma. From what I know of
the code I doubt if there is anything particularly squeak-centric. Magma
has to be easier to port than Seaside, since it doesnt use any
complicated stuff like continuations.

just a thought

Keith


_______________________________________________
seaside mailing list
[hidden email]
http://lists.squeakfoundation.org/cgi-bin/mailman/listinfo/seaside

Dale Henrichs wrote

Dale Henrichs wrote:

> A large number of our customers use the combination of VW and GemStone
> for persistence. The product GemBuilder for Smalltalk (GBS) runs
> inside of a VW (or VA) image and provides connectivity to a GemStone
> data base.
>
> So technically VW does have a pretty good OODB-based persistence option.
>
> Take a look at  
> http://seaside.gemstone.com/docs/Announcement-ESUG2007.htm where we
> describe GemStone/S LE which provides persistence for VW, the main
> difference between GemStone/S LE and GemStone/S Web Edition (GLASS) is
> that GemStone/S LE is not free.

Okay, okay, you get value for your money --- VW, VA support,
Solaris/AIX/HP, 2 CPUS, 8X larger repository, 2X shared page cache, and
technical support--- but hey other than that they're the same:)...

(still suffering from head cold),

Dale
_______________________________________________
seaside mailing list
seaside@lists.squeakfoundation.org
http://lists.squeakfoundation.org/cgi-bin/mailman/listinfo/seaside