Which database am I using?

["Mark R. Diggory" <md...@latte.harvard.edu>]

Here's an interesting issue I've bounced across.

If I'm using the embedded driver to access the database locally. The 
embedded driver looks for the db location in the system property if it 
can't find it it goes for a default local to the current working 
directory (which I suspect can vary across OS's and Servlet Containers).

<!-- Snip from embeded DataBaseImpl -->
   public static final String PROP_XINDICE_CONFIGURATION = 
"xindice.configuration";

   // Default configuration if a system.xml file isn't available.
   public static final String DEFAULT_CONFIGURATION = "<xindice>" +
      "<root-collection dbroot=\"./db/\" name=\"db\">" +
      "<queryengine>" +
      "<resolver autoindex=\"false\" 
class=\"org.apache.xindice.core.query.XPathQueryResolver\" />" +
      "<resolver 
class=\"org.apache.xindice.core.xupdate.XUpdateQueryResolver\" />" +
      "</queryengine>" +
      "</root-collection>" +
      "</xindice>";

Now, If I'm using the XindiceServlet to startup xindice it first looks in

<!-- snip from web.xml-->
         <param-name>xindice-configuration</param-name>
         <param-value>/WEB-INF/system.xml</param-value>

then if thats not set it goes to
<!-- Snip from XindiceServlet -->
Xindice.DEFAULT_CONFIGURATION

then this all can get overridden if the following is set.
<!-- Snip from XindiceServlet -->
// Let's see if the property was specified.
String home = System.getProperty("xindice.db.home");               
               

How can I make sure that the embedded driver and and my servlet config 
are always working with the same database?

1.) It looks like if the embedded driver is defaulting to 
DEFAULT_CONFIGURATION while the Servlet Config could run off and 
establish its db at "xindice.db.home" instead of at DEFAULT_CONFIGURATION.

2.) It looks like to really make sure both are using the same config I 
need to set the System.property "xindice.configuration" to be the same 
as my <param-name>xindice-configuration</param-name>. Setting the system 
property may not be possible in some containers. This would make it 
impossible to have separate db instances in separate webapplications 
wouldn't it?

Not sure of a solution, I've noticed some comments in the source that 
xmldb group is working on a new configuration interface?

   /**
    * Creates new <code>DatabaseImpl</code> instance. The configuration is
    * loaded from the file defined in the PROP_XINDICE_CONFIGURATION system
    * variable.
    *
    * This is only a temporarly solution since the question of a new init
    * method is raised in the xmldb:api group. Another solution could be to
    * use the Configurable interface and only create the database when the
    * getCollection method is called.
    */

Vladimir, You may get a patch or two out of me soon!  ;-)
-Mark

Re: Which database am I using?

[Henrik Vendelbo <hv...@bluprints.com>]

Was this ever discussed. I am trying to make embedded Xindice to work with
the right directory, with little luck.

Even if it works, defining a property on the command line is not an option,
so I tried

DatabaseManager.setProperty(DB_HOME_PROP,"C:\\demo\\db");

Database database = (Database) Class.forName(driver).newInstance();


System.setProperty(DB_HOME_PROP,"C:\\demo\\dspc\\db");

DatabaseManager.registerDatabase(database);



Neither works when using the xindice-embed.



So perhaps I should sub-class the DatabaseImpl ?





----- Original Message ----- 
From: "Mark R. Diggory" <md...@latte.harvard.edu>
To: <xi...@xml.apache.org>
Sent: Saturday, April 12, 2003 1:40 AM
Subject: Which database am I using?


> Here's an interesting issue I've bounced across.
>
> If I'm using the embedded driver to access the database locally. The
> embedded driver looks for the db location in the system property if it
> can't find it it goes for a default local to the current working
> directory (which I suspect can vary across OS's and Servlet Containers).
>
> <!-- Snip from embeded DataBaseImpl -->
>    public static final String PROP_XINDICE_CONFIGURATION =
> "xindice.configuration";
>
>    // Default configuration if a system.xml file isn't available.
>    public static final String DEFAULT_CONFIGURATION = "<xindice>" +
>       "<root-collection dbroot=\"./db/\" name=\"db\">" +
>       "<queryengine>" +
>       "<resolver autoindex=\"false\"
> class=\"org.apache.xindice.core.query.XPathQueryResolver\" />" +
>       "<resolver
> class=\"org.apache.xindice.core.xupdate.XUpdateQueryResolver\" />" +
>       "</queryengine>" +
>       "</root-collection>" +
>       "</xindice>";
>
> Now, If I'm using the XindiceServlet to startup xindice it first looks in
>
> <!-- snip from web.xml-->
>          <param-name>xindice-configuration</param-name>
>          <param-value>/WEB-INF/system.xml</param-value>
>
> then if thats not set it goes to
> <!-- Snip from XindiceServlet -->
> Xindice.DEFAULT_CONFIGURATION
>
> then this all can get overridden if the following is set.
> <!-- Snip from XindiceServlet -->
> // Let's see if the property was specified.
> String home = System.getProperty("xindice.db.home");
>
>
> How can I make sure that the embedded driver and and my servlet config
> are always working with the same database?
>
> 1.) It looks like if the embedded driver is defaulting to
> DEFAULT_CONFIGURATION while the Servlet Config could run off and
> establish its db at "xindice.db.home" instead of at DEFAULT_CONFIGURATION.
>
> 2.) It looks like to really make sure both are using the same config I
> need to set the System.property "xindice.configuration" to be the same
> as my <param-name>xindice-configuration</param-name>. Setting the system
> property may not be possible in some containers. This would make it
> impossible to have separate db instances in separate webapplications
> wouldn't it?
>
> Not sure of a solution, I've noticed some comments in the source that
> xmldb group is working on a new configuration interface?
>
>    /**
>     * Creates new <code>DatabaseImpl</code> instance. The configuration is
>     * loaded from the file defined in the PROP_XINDICE_CONFIGURATION
system
>     * variable.
>     *
>     * This is only a temporarly solution since the question of a new init
>     * method is raised in the xmldb:api group. Another solution could be
to
>     * use the Configurable interface and only create the database when the
>     * getCollection method is called.
>     */
>
> Vladimir, You may get a patch or two out of me soon!  ;-)
> -Mark
>
>
>
>