Whether the future of databases is the traditional, relational and SQL model with XML technologies incorporated into it or a new XML-based model is a matter of debate, according to panellists during a session April 23 at the Software Development Conference & Expo in San Jose, Calif.
The fate of XML and SQL dominated the discussion, which featured officials from companies such as Oracle Corp., Sun Microsystems Inc., and IBM Corp.
“I think that XML will become the dominant format for data interchange,” with its flexibility and ability to provide self-description, said Don Chamberlin, a database technology researcher at IBM. Relational databases, he said, will be fitted with front ends to support XML and process queries based on the XQuery standard.
XML will become the “lingua franca” for exchange of data, Chamberlin said. “We’ll also see some large relational systems adapt to XML as a native format,” Chamberlin said.
Technologists are in the early stages of development of XML technologies, he said. “We need to do a lot of implementation work on how to index XML data,” Chamberlin said.
SQL will not go away, but there are new data formats for which it just was not designed, he said.
Sun’s Rick Cattell, a distinguished engineer at the company, had a less dominant outlook for XML, saying very few people are going to store XQuery data in an XML format. “I think the momentum behind relational databases is insurmountable,” Cattell said, adding that he was drawing on his experience with object-oriented databases, which were unable to unseat relational databases in enterprise IT shops.
Developers, Cattell said, will need tools to convert relational data to XML and vice versa.
Another panellist, Daniela Florescu, chief technology officer at XQrl Inc., said she was “pretty optimistic [about] the performance of XML databases.” Documents will be stored natively in XML, she said. XQrl offers a version of the XQuery XML query language.
Currently, performance on the Web is hindered because of translations between Java and XML data formats, Florescu said. “I don’t think we will have good performance as long as we have people marshalling data from XML to Java and back,” Florescu said.
She went so far as to predict that eventually, an extension of XQuery will replace both Java and SQL, drawing a sharp retort from Cattell, whose company developed the Java programming language.
“I don’t think XQuery is ever going to replace SQL or Java,” but there may be a query language to replace SQL, Cattell said.
The next step in the evolution of databases is to provide a more powerful way to query them than what is being done on search sites such as Google today, said Cattell.
Panellists also touched on topic such as tuple space technology, which is intended to make it easier to store and fetch data by recognizing patterns.
Tuple space technology is “interesting, but I wouldn’t predict that it’s going to take over the world,” since much more research needs to be done and most people are not building production applications based on it, Cattell said. Cattell also said in-memory database technology is a “no-brainer,” but there is not enough memory available yet to accommodate it.
Microsoft Corp. Distinguished Engineer Jim Gray stressed the importance of self-managing database technology in bringing administration costs down.
“The real challenge we face is to make computers self-managing so the management cost is less than the capital cost,” Gray said.
Gray also questioned the value of deploying database queries in a peer-to-peer format when there is enough inexpensive processing power in individual computers.
“The problem with p-to-p computing for databases is you have to send a lot of data around and $1 will buy you a lot of computing,” Gray said.
Panellists also fielded a question about the importance of standards in the database development process. Panellist Jim Melton, consulting member of the technical staff at Oracle, said in some cases “de jure” standards developed through standards bodies are appropriate, such as with SQL. In other cases, standards can be developed through consortia, such as with ODBC, Melton said.
Melton said he is part of a vendor group called SQLX that has been working for a year to define ways to bring SQL and XML closer together. The group in mid-2003 plans to publish a specification called SQL/XML, which will contain publishing functions for the two formats.
