> -----Original Message----- > From: Gunnar R�nning [mailto:[EMAIL PROTECTED]] > Sent: Friday, September 28, 2001 10:25 PM > To: [EMAIL PROTECTED] > Subject: Re: DB proposal > > > * "Howard Lin" <[EMAIL PROTECTED]> wrote: > | > | I think it's a good idea that one XML file contains one > database. Now > > Could you please clean up the terminology a little ? We are > talking about > an XML schema, but what is the definition of a database ? > Mayve you mean > SQL schema, but call it database ? > -- Actually I mean an XML representation of a SQL schema. XML schema is a totally different thing (see w3c.org, which is a replacement for DTD). So strictly speaking, in XML format, we should use "schema" instead of "database" element, since the same database can contain multiple schema and the same schema can live in different (physical) databases. I've been thinking that if we use "schema" element, and then "database" can be an attribute of this element, like this: <schema name="turbine" database="dbserver1, dbserver2" ...> <table /> <table /> </schema> <schema name="system" database="dbserver2" ...> <table /> <table /> </schema> In the property file, we specify dbserver1 and dbserver2: dbserver1.url=... dbserver1.driver=... ... dbserver2.url=... ... I'm not sure how to implement this yet, since this will change the map class for the BaseXXX/BaseXXXPeer class. This design may be useful for implementing multiple database support for fail over and redundancy. In the map class, we can have a list of databases (instead of one) and somehow let user specify a default one and a backup one through property file.
Howard Lin --------------------------------------------------------------------- To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED]
