[From nobody Tue Aug 24 09:42:40 2004 X-Mozilla-Status2: 00000000 Message-ID: <3A0C51ED.D149EE02@middle.net> Date: Fri, 10 Nov 2000 12:52:13 -0700 From: Mark Butler <butlerm@middle.net> X-Mailer: Mozilla 4.75 [en] (WinNT; U) X-Accept-Language: en MIME-Version: 1.0 To: Luke Call <lacall@onemodel.org> Subject: Re: [om-list] Re: System Design References: <3A0021BB.60000@onemodel.org> <3A021BFE.BE0D6B0B@middle.net> <3A0957C8.7010602@onemodel.org> Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Luke Call wrote: > That is exactly why I suggest we store our structures in a 3rd-party DB > for now. PSE was cheap and effective for a quick prototype (at leaste it > was a few years ago; it was a free Java OO database), and there are many > options to choose from. I generally agree. We can store our data structure in any kind of database once we agree what it is. The only tradeoff is efficiency depending on how close the mapping is. I expect that once we have a common logical model different classes of applications could use different database types and data representations to store the same information. As an example, XML is a both a text interchange format and a logical meta-format for hierarchically structured data. Many modern systems speak to each other in the canonical text format of XML, but no one stores any significant amount of data that way, rather they convert it to a native database for storage and retrieval. Those native databases are currently mostly relational, but there are several up and coming databases that can convert and store XML data in a manner suitable for random indexed key access and processing. XML is a bit of an ugly format, but is extremely easy to parse, which contributes to its popularity. Before we start mapping our proposal to a pre-existing database, we really need to agree on a common logical meta-model. A standard text based format corresponding to that representation is then extremely valuable to insure the portability and interoperability of various programs based on the same logical meta-model. Some applications, for example, may only need a read only extract of information about a particular field and good get along just fine with importing a text extract of a more comprehensive database. - Mark -- Mark Butler ( butlerm@middle.net ) Software Engineer Epic Systems (801)-451-4583 ]