[fdo-internals] Updated FDO RFC 23 For Review

[Brent Robinson]

Hi Traian,

It would be the last case. The RDBMS providers cache the schemas but the first time retrieval can be expensive when there are many classes.

Brent.

From: fdo-internals-bounces at lists.osgeo.org [mailto:fdo-internals-bounces at lists.osgeo.org] On Behalf Of Traian Stanev
Sent: Thursday, July 17, 2008 12:53 PM
To: FDO Internals Mail List
Subject: RE: [fdo-internals] Updated FDO RFC 23 For Review


The impact on non-RDBMS providers like SDF is a bit unclear to me. It seems like there are two cases.


(1)    FDO connection is kept open. In such case DescribeSchema operation is free, since the schema is cached internally by the connection.

(2)    FDO connection is opened and then those new commands are executed - in this case the schema would have to be deserialized, in its entirety, which would not make the new commands perform any faster than DescribeSchema.

It seems to me like making the RDBMS providers cache their schema internally is something that would make the extra commands unnecessary, and would only limit code changes to providers which do have a problem with DescribeSchema, instead of having either all providers implement new commands, or having client code have two code paths everywhere it deals with getting a schema. However, I do not know enough about the RDBMS providers to be sure if caching the schema is not possible in their case. Or are we talking about the case where getting the schema even once, to cache it, is too expensive (like if there are 1 million classes in Oracle)?


Traian



From: fdo-internals-bounces at lists.osgeo.org [mailto:fdo-internals-bounces at lists.osgeo.org] On Behalf Of Jason Birch
Sent: Thursday, July 17, 2008 12:41 PM
To: FDO Internals Mail List
Subject: RE: [fdo-internals] Updated FDO RFC 23 For Review

I like this approach, though for consistency it would be nice if all of the providers implemented these new commands as soon as possible.

>From my perspective, having to special case everything based on capabilities can get a bit frustrating, especially for lowly scripters who barely understand how to tie their shoes :)

Jason

From: fdo-internals-bounces at lists.osgeo.org [mailto:fdo-internals-bounces at lists.osgeo.org] On Behalf Of Ronnie Louie
Sent: Thursday, July 17, 2008 00:39
To: FDO Internals Mail List
Subject: [fdo-internals] Updated FDO RFC 23 For Review

RFC 23 (http://trac.osgeo.org/fdo/wiki/FDORfc23) has been updated and re-posted for review.   In particular, the previously proposed changes to DescribeSchema have been dropped, and replaced with a new DescribeClasses command.  Also the API command names for enumerating schemas and classes have been updated to GetSchemaNames and GetClassNames.

Please review the new proposal and reply to this list by July 23.

Thanks
Ronnie
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