How to link records. Re: Question Backlog for Valentina mailing list.

[Ruslan Zasukhin]

On 11/16/05 9:05 AM, "Ed Kleban" <Ed at Kleban.com> wrote:

> Ah, I found it.  It's the LinkRecords and UnlinkRecords commands.
> 
> Hmm. I'll have to think about this.  I guess you get a performance advantage
> from not having to actually put data into the table in order to create a
> link.  Therefore you don't have to visit all the records, but rather just
> stuff the relation info into the Binary Link table.   I guess that makes
> sense.

BinaryLink have many benefits.
 
One of the most important is:
    you get Tables as Tables. Links as Links.
    Structure of Tables do not depend now on how many links around.


> And I suppose that if the base tables are on disk, but you only need a
> temporary binary link in RAM, you get a big boost as well.

I have not think about this, but probably yes.

AGAIN. With such tmp link, you DO NOT change tables.
 

> But if both are retained on disk, does this end up taking less storage or
> more?  

YES. 2 times less than usual M M table

> I guess if you're only storing a list of which records have
> relations, then you need a Ulong index for both each link to designate one
> record in each table, but you don't have to have space allocated in
> baseTable records that aren't linked.
> 
> Aha!  That's the big speed gain.  When you need to check relations you don't
> have to visit every record in one of the tables to see if there's a link,
> you only need to scan the list of established links in the binary Vlink.

And this is also. As well as other

-- 
Best regards,

Ruslan Zasukhin
VP Engineering and New Technology
Paradigma Software, Inc

Valentina - Joining Worlds of Information
http://www.paradigmasoft.com

[I feel the need: the need for speed]