[OSGeo-Discuss] Re: "git" like for geodata management

[maning sambale]

Perhaps the only online service I can think of that is similar to what
I mentioned is openstreetmap's API:
http://wiki.openstreetmap.org/wiki/API_v0.6

On Mon, Sep 27, 2010 at 3:13 PM, Kalyan Janakiraman
<Kalyan.Janakiraman at lpma.nsw.gov.au> wrote:
> Hi
>
>
>
> Versions are also used to demarcate the the geospatial transaction boundary.
> I didn’t see this point articulated.
>
>
>
> We have been sucessfully running replication of ArcSDE geodatabase from data
> maintenance environment to different geodatabase repositories (about 150
> repositories) for many years now through event-driven mediation framework.
> Because we had used the event-driven mediation approach, we could replicate
> irrespective of the version or the vendor.
>
>
>
> Because ESRI didn’t support robust replication before, we did this
> ourselves. In gist the version is boundary of each geospatial transaction.
> When a version is posted, the transactions in it are picked up and shipped
> across as XML event feeds.
>
>
>
>
>
> I published this as a paper. I can send it to anyone interested.
>
>
>
> -       Kalyan
>
>
>
> From: discuss-bounces at lists.osgeo.org
> [mailto:discuss-bounces at lists.osgeo.org] On Behalf Of Ragi Burhum
> Sent: Friday, 24 September 2010 4:06 AM
> To: discuss at lists.osgeo.org; Noli Sicad
> Subject: [OSGeo-Discuss] Re: "git" like for geodata management
>
>
>
> Hi Noli,
>
>
>
> thanks for the link. That is definitely a step in the right direction, but
> it is hardly comparable to git ArcSDE versioning at that.
>
>
>
> The article and sample code you describe above generates hashes for all rows
> and tables in the db and compares them to the target db. So 1 million rows
> in a db, regardless if the two dbs are identical, would cause 1 million
> hashes to go over the wire. Every single time you ask to sync you pay the
> price.
>
>
>
> Git and ArcSDE keep track of changesets, and when it is time to synchronize,
> they exchange that changeset and apply it. One insert? That is all that
> needs to be sent.
>
>
>
> Another issue is that there is nothing about conflict resolution there (what
> happens when you delete one row in one db and modify it in another one?).
> There is also the problem of allowing multiple versions of the data in the
> same db (Like having multiple heads).
>
>
>
> Regardless, thank you for the link,
>
>
>
> - Ragi
>
>
>
>
>
> Date: Thu, 23 Sep 2010 13:22:17 +1000
> From: Noli Sicad <nsicad at gmail.com>
> Subject: Re: [OSGeo-Discuss] Re: "git" like for geodata management
> To: OSGeo Discussions <discuss at lists.osgeo.org>
> Message-ID:
>             <AANLkTi=3anC4BAANd4HK9UUZFsasXn-8ybPNKYoNG+Fw at mail.gmail.com>
> Content-Type: text/plain; charset=ISO-8859-1
>
> PostgreSQL Synchronization Tool  --- psync [1]
>
> " The article introduces a method of synchronizing two PostgreSQL
> databases. Although, this seems to be an easy task, no product (slony,
> londiste, ...) really satisfied the needs within the maps.bremen.de
> project. Either they have special prerequsits that didn't apply for
> our problem or they didn't support synchronizing of large objects.
>
> Large objects are used to store tiles of a street/aerial map within
> PostgreSQL. My GIS-server queries the database and gets the tiles out.
> By using this construction we are getting a flexible infrastructure
> for updating and maintaining different versions of the maps.
>
> Everything was working fine until the service needs to be spread over
> three servers. How can we easily synchronize the databases? I really
> found no really working solution that is clean and easy to use.  "
>
> [1]http://www.codeproject.com/KB/database/psync.aspx
>
>
> Noli
>
> On 9/23/10, Ragi Burhum <ragi at burhum.com> wrote:
>
> Are you looking for an alternative to (1)ESRI's versioning, (2)ESRI's
>
> disconnected editing, or a mix of both (3)git like? the scenario that you
>
> described first was more like (2), but this one fits (1).
>
>
>
> I would love to see something like (3), but truth of the matter, AFAIK,
>
> there is nothing like that implemented for geo (yet).
>
>
>
> On Sep 22, 2010, at 9:00 AM, discuss-request at lists.osgeo.org wrote:
>
>
>
> On Wed, 2010-09-22 at 12:10 +0800, maning sambale wrote:
>
> Any real world cases for this?
>
>
>
> Imagine the following scenario:
>
>
>
> * 50 ~ 70 digitizers
>
> * 5 QA
>
> * 1 Manager
>
>
>
> Each QA has 10 digitizers assigned. After all the data is validated, the
>
> manager merges it and generates the geodb.
>
>
>
> All users work against the same DB, most of them linked. This causes
>
> disconnections, duplicated data, and lots of random errors.
>
>
>
> Also, they can't be forced to work on different DB's because they are
>
> all working on the same project, at the same time.
>
>
>
> This is the real scenario of GISWorking (http://www.gisworking.com/), a
>
> company we are working with.
>
>
>
> It would be perfect to have smaller groups (ideally 1 person), working
>
> against separated databases, but that can be synchronized with the rest
>
> of the data when needed.
>
>
>
> Then each QA merges data from the people he supervises. After it's
>
> validated the manager merges the complete dataset, and generates the
>
> final "product".
>
>
>
> I don't know if this it's the exact same case, but we are working on it
>
> with a similar approach.
>
>
>
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-- 
cheers,
maning
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