On 9/29/01 10:34 AM, "Howard Lin" <[EMAIL PROTECTED]> wrote:
>> -----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). We can it an XML descriptor or whatever as not to confuse people I suppose. One database per descriptor. You won't be able to create multiple databases with a single descriptor. The <database> element will actually be a representation of the layout of a database. I don't really like the <schema> thing. > 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] -- jvz. Jason van Zyl http://tambora.zenplex.org http://jakarta.apache.org/turbine http://jakarta.apache.org/velocity http://jakarta.apache.org/alexandria http://jakarta.apache.org/commons --------------------------------------------------------------------- To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED]
