[seek-dev] FW: OGSA-DAI Query Number 60

[Bing Zhu]

-----Original Message-----
From: OGSA-DAI Support [mailto:support at ogsadai.org.uk]
Sent: Friday, August 22, 2003 6:53 AM
To: bzhu at sdsc.edu
Subject: OGSA-DAI Query Number 60



Dear Bing,

Many thanks for submitting your query, I've assigned it OGSA-DAI Query
Number 60.  Please refer to this number in all correspondence regarding
this query.

> I have successfully installed OGSA-DAI 3.0 in my laptop and ran the
> query example as instructed in manual. Then I had a quick question
> regarding as how can I include database name, user name and password
> in the perform document to submit my query as a ogsa-dai client by the
> following command from your installation manual.
>
> C:\ogsadai>java uk.org.ogsadai.client.Client
http://localhost:8080/ogsa/services/ogsadai/DAIServiceGroupRegistry
c:/ogsadai/examples/GDSPerform/JDBC/query/select1Row.xml
>
> I read both GDS and GDFS documents and could not find such info.
>
> It looks that we have to specify a database in driver manager element
> as I can see from the example file, dataResourceConfig.xml.

The database name, username and password are specified in the GDSF
configuration files that are kept in <TOMCAT-OGSA-ETC> as described in
Sections 4,5 and 6 of the GDSF document.  The database name is in the
dataResourceConfig.xml file and the username/password in the
ExampleDatabaseRoles.xml file.  You don't need to, and in fact can't,
specify these things in perform documents.  Each GDSF represents a
particular data resource and so the database name, username and password
only need to be specified once for that data resource.  Perform documents
passed to a GDS created by this GDSF will then use the database, username
and password that you've specified in its configuration.

There are several examples of perform documents in the examples\GDSPerform
directory of OGSA-DAI for both relational and XML data resources.

> And also, is it possible to specify a page size for the query result
> to be returned. In many cases, a query result can have huge amount of
> data which can cause significant performance issue if it is treated as
> just one XML document.

If you're retrieving that much data then it might be worth while
investigating the different delivery methods of OGSA-DAI as described in
Section 4.6 of the GDS document.  The deliverFromGDT and deliverToGDT in
particular can deliver the data in blocks.

Hope this helps.
Best Regards,
Jeremy Nowell

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