[Developers] "link" and the "operation"

[Christopher Dummy]

Thanks! that is very helpful.


On Jan 16, 2008 6:18 PM, Alec Flett <alecf at metaweb.com> wrote:

>
> On Jan 16, 2008, at 3:43 PM, Christopher Dummy wrote:
>
> I couldn't find any documentation on /type/link which is used for
> properties. I'm trying to understand what some of the values can be and what
> they mean.
>
>
> This doesn't necessarily help a huge amount, but you can look at the
> schema for "link":
>
> http://www.freebase.com/view/schema/type/link
>
>
> Here's the short documentation which I'll try to get into a help topic:
>
> type: I believe this will always be "/type/link"
>
> timestamp: the time the link was created
>
> creator: points to the user (i.e. /user/alecf) who created it
>
> master_property: the property that this link represents (like
> /film/film/cast)
>
> reverse: whether or not the master_property is pointing to or away from
> the item
>
> operation: "insert" means it is a normal link, that doesn't supercede any
> other value. "update" means that it is a normal link that "overwrote" a
> previous link. "delete" means the link actually represents the deletion of a
> different link. Since freebase's database is append-only, the way to
> "delete" a link is to overwrite it with a "tombstone" link - that's what
> "delete" is
>
> valid: a boolean indicating if this current link is active - i.e. wasn't
> deleted by another link.. and so yeah you're right that a "delete" link
> isn't really valid or not, since it is really making a different link
> "invalid"
>
> attribution: a more complex subject - basically this may point to a user
> or a node which describes some sort of attribution, such as what datasource
> a particular link came from... (i.e. if someone asserted that "the
> population of china is 1 billion people" according to the CIA World Fact
> Book) this isn't really used right now.
>
> I hope this gets you started. The master_property/reverse stuff can be a
> little confusing at times.. my advice there is just to play around with it
> to understand how it works until we have more extensive documentation.
>
> Alec
>
>         {
>           "guid": "#9202a8c04000641f8000000000014a39",
>           "link": {
>             "timestamp": "2008-01-16T22:08:24.0000Z",
>             "operation": "insert",
>             "valid": false
>           },
>           "name": "Electronic music"
>         },
>         {
>           "guid": "#9202a8c04000641f8000000000014a39",
>           "link": {
>             "timestamp": "2008-01-16T22:11: 12.0000Z",
>             "operation": "delete",
>             "valid": null
>           },
>           "name": "Electronic music"
>         }
>
> I assume the "valid" refers to whether the link is valid or not. the UI
> will display just the valid links. For that reason, "delete" doesn't have a
> true or false value since it doesn't represent a link. Is that correct?
>
> I've seen the operations  "insert", "update", "delete".
>
> Are there any other operations that can happen? Is there a time when the
> "delete" operation might have something other than a null for valid?
>
> --
> Christopher Cotton
> Zing/Dell Engineer
> http://zing.net/ _______________________________________________
> Developers mailing list
> Developers at freebase.com
> http://lists.freebase.com/mailman/listinfo/developers
>
>
>
> _______________________________________________
> Developers mailing list
> Developers at freebase.com
> http://lists.freebase.com/mailman/listinfo/developers
>
>


-- 
Christopher Cotton
Zing/Dell Engineer
http://zing.net/
-------------- next part --------------
An HTML attachment was scrubbed...
URL: http://lists.freebase.com/pipermail/developers/attachments/20080117/62b6dfba/attachment.htm